b*******s
发帖数: 6139 | 1 "
The Minolta Alpha camera system was a collection of photographic equipment
from Minolta. The system used a lens mount of the same name, also known as
the A mount, with a flange focal distance 44.5 mm. ... The mount is now used
by Sony, who bought the SLR camera division from Konica Minolta, Konica and
Minolta having merged a few years before.
When Sony acquired Konica Minolta's camera technologies in 2006 they chose
the "α" brand name (already in use by Minolta in Asia) for their new "Sony
α" ... 阅读全帖 |
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k****t
发帖数: 12697 | 2 偶把REAR ELEMENT RETAINER RING SAND 掉了, 粗看INFINITY 正好行, 细看得WEEKEND
白天LV 对远处的山.
说要SAND SPACER 真奇怪. MD FLANGE DISTANCE 43.5, EF 44.0. MOUNT 厚度可以多出
0.5MM.
拿掉的原MOUNT 厚1.05 到1.10MM, 换上去的M42/Ef ADAPTER 厚1.40MM, 多了0.3到0.
35MM 还要SHIM. 不懂为啥要SAND. |
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x5
发帖数: 27871 | 3 c-mount的flange distance比DSLR短太多，不能直接用
有专门的adapter，不过adapter的价钱也和一个D90差不多了 |
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k****t
发帖数: 12697 | 4 4/3 注意好, SENSOR小, FLANGE DISTANCE 也小,没MIRROR, 价格便宜. |
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r*******d
发帖数: 958 | 5 挖个坑
我梦想有个公司出来搅局，搞一个全副sensor的革命机，sensor到flange距离小于40mm。
这样什么老头都可以弄个adapter搞上去，
价钱就定1000刀了，爽啊
我要是棒子三爽的头我就这么搞，一下抓住了遗老遗少/穷人的心，
老头市场一片活跃，神医们从搞GF2改成搜M42，Canon FD。。。
我赌2年内FF革命机问世 |
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b****r
发帖数: 17995 | 6 有可能吗，sensor到flange距离小于40mm，又是全副 |
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r*******d
发帖数: 958 | 7 还是很少人愿意折腾转接环的
镜头能不能用转接环整到别的机身上，跟镜头和机身的registration distance (
flange distance)有关
跟设计初衷没关系，
pentax nikon的手动镜头在自家AF机身上都能兼容 |
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k****t
发帖数: 12697 | 8 1.2. 此镜就是没能达给LEICA 代工的R24, R24 价$800, 这个$200 到$250.
3. MD24 比较难改因为屁股上三爪只有个薄片能拧下(5个罗丝).整个爪必须锯掉.
4. 拧掉4个罗丝, MOUNT 下来, MD/MC 镜头麻烦处是一般控制光圈的CAM 在MOUNT 上,
MOUNT 必须保留,只有ROKKOR PG 58/1.2, PF 58/1.4, 85/1.7 35-70/3.5 四个镜头不
在MOUNT 上, 右边那个可以直接扔掉.
5. 大部分WORK 在MOUNT 上, 镜身TAPE 上防止光圈环掉下来把小球丢了.
6. CAM 从MOUNT 上拆下
7. 没车床, 只好锯.
8. 三爪部分锯下
9. MD 的FLANGE DISTANCE 比EOS 小0.5MM, MOUNT 要磨掉这多, 所以上面锯的毛糙点
不要紧反正要磨, 先用沙轮几粗磨.
10. 细磨. 镜头盖大小正好FIT 凹下处,当HANDLE 用.
11. 边磨边用游标尺量不能过头太多, 稍微过点安装是得颠回来, 这个头是FLOATING,
不能冲过无穷远. 这磨完了. |
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k****t
发帖数: 12697 | 9 12. 4块钱的M42 > EOS 接环, 先边上一圈锯个痕扳掉.
13. 14. 粗磨细磨把整个FLANGE 的厚度去掉.
15. 光圈环上的MD, MC TAB. MD TAB 要挫短.
16. CAM 上光圈拨杆用DREMEL 小沙轮锯短.
17. CAM 装回到MOUNT 以确定何处钻洞把EOS 的三爪装上
18. MARK 好三个洞.
19. 1/16" 钻头钻洞. R 是要对准镜身上原来的红点, 以后装CANON 上也是红点对红点.
20. 另面DREMEL 扩洞至1/8" 把罗丝头沉入.
21. MOUNT 上一样1/16" 洞, 罗帽拧上. 罗丝是METRIC 1.6MM
22. 另面
23. 左边,上面的罗帽都影响CAM 的运动, CAM 得用DREMEL 磨两缺口. |
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e**n
发帖数: 5876 | 10 http://photorumors.com/2011/06/29/leaked-pentax-document-indica
泄出的官方pdf文件, K-mount APS-C DSLRs, the 645D and the Q system 三条线, 木
有APS革命机和FF.
Q&A section:
A1: “Q” stands for Queen and Quality;
A11: Body is made in Philippines, “High Performance” lenses are in Vietnam
whereas the “Toy” lenses are made in Thailand.
A17: The flange focal length is 9.2mm.
A20: A brand new image processing engine is used. It is NOT a PRIME!
A21: The Q has no AA filter.
A26: There is no PEF (compressed Pentax RAW) fil... 阅读全帖 |
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n**b
发帖数: 13203 | 11 咋解释也没用，反正就是个杯具
"One of my good sources explained why the new Zeiss 24mm f/1.8 lens is so
large: “The large lenses have optics that are usable, with minimal
modification, with SLT cameras. NEX-7 is a high quality photographic tool.
Shorter size lenses would have very short distance of the rear lens element
to the film plane. With small exit lens on wide lenses there would be too
much light fallout. That is why a high quality WA lens needs to be bigger.
The problems with NEsystem. Very short flang... 阅读全帖 |
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n**b
发帖数: 13203 | 12 价格有点儿吓人
Pricing : around 1300including the 35mm lens. The other optics being
around 600(“according to their informations”, and “to be confirmed”)
Sensor : APS-C 1.5x, CMOS, Fuji “X-Trans” technology. Photosites pattern
is 6 sides (as opposed to Bayer 4 sides). There is no anti-moiré filter,
which will allow better resolution. [Note that there is no word about an
organic sensor] Lenses are full metal. “Fujinon XF optics are announced as
exceptional”, They are 18 f2.0, 35 f1.4, 60 f2.4 macro (equi... 阅读全帖 |
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h*********u
发帖数: 10868 | 13
Flange focal distance
Sony E-mount 18 mm
Pentax K-mount 45.5 mm |
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d******a
发帖数: 32122 | 14 Highly secret information directly from Japan
The mirror-less system camera from Canon is called D-IX
2012-03-31 As the only major manufacturer Canon has been no mirror-less
system cameras. But this will change in the summer of 2012, as we could
learn from internal circuits from Canon Japan. The digitalkamera.de
editorial was a first photo of the new D-IX leaked. The original EOS IX APS
SLR, the IX-D, however, has little in common, it leans much more on the
PowerShot G1 X. That is, given the lar... 阅读全帖 |
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g*******n
发帖数: 1188 | 15 "M42-eos flange adapter for the most m42 lens, apart from pentax takumar."
??
45MM |
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k****t
发帖数: 12697 | 16 The effects of flange thickness is neglegible, especially on telephoto
lenses. But it a small variance indicates a tight manufacturing tolerance
and better quality control. Ideally it should exactly 1.5mm but it is hard
to do so they make it just under 1.5. The larger the tolerance the thinner
they have to make it, to ensure every piece is under 1.5mm. |
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k****t
发帖数: 12697 | 17 有可能没到无穷远(笨猫你中彩了).
可靠的是拿卡尺量ADAPTER 的FLANGE 厚度.
或着你拆的时候把无穷远调调
转接靠铺的是全幅带LV 再换EGS屏.比如5D2.
7D 上测光误差好几档. 找罪受 |
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i****o
发帖数: 1183 | 18 FF没戏了
"The EF-M mount is 58mm in diameter, with a flange distance of 18mm from the
bayonet to the sensor. As the image above clearly shows it's matched
specifically to the APS-C sensor size. So don't expect a future full frame
EF-M mount camera - it's not going to happen." |
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x5
发帖数: 27871 | 19 Leica M flange distance是27.8mm
Canon EF是 44 mm
差16.2mm，但你看他改的 M卡口和原来的EF卡扣基本是平的，这没啥用吧，近视眼 |
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f**s
发帖数: 968 | 20 链接在此：
http://www.kenrockwell.com/tech/8mm-f35.htm
8mm f/3.5 Fisheye
Pro-Optic, Samyang, Rokinon, Bower &c. (2009-)
© 2010 KenRockwell.com. All rights reserved.
Intro Specs Performance Compared Recommendations
8mm f/3.5 Fisheye, Pro-Optic Nikon AI-s version. enlarge. ($290, Korean, no
filters, 13.8 oz./391g). This one came from this link to it at Adorama (also
specifically in Nikon, Canon EOS, Pentax/Samsung and Minolta Maxxum/Sony
mounts). It also comes branded as Bower, also specif... 阅读全帖 |
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p*******0
发帖数: 420 | 21 好吧，我承认我是穷人，只买的起5n.
微单也就nex和k 01了吧。k 01我觉得也不能算微单了，flange都没有变，就是一个取
消了mirror的单反。单反mirror lock up也可以吧。 |
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l*******y
发帖数: 4006 | 22 我觉得这个观点很正常。 无可否认， c+是现今为止， 最hassle free的单反选择。
自动头不用担心能不能自动对焦， 手动头不用担心flange。 |
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l*******y
发帖数: 4006 | 23 我个人感觉。 D5200和D3200， 没有built in motor的不能对焦。 连副厂17-50都分了
BIM和non-BIM的版本, 想玩老头的真的要做很详细的研究. 玩转接， nikon头接佳能很
容易， nikon相机接别的头就要查flange， 而且很多头接不了。
再看看d600和5D的不同待遇， 出个问题nikon机都是后妈生的。 |
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l*******y
发帖数: 4006 | 25 短flange的边角问题不是靠image processor就能解决的。
with |
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j****a
发帖数: 1406 | 26 F->m43, sigma 18-50 我去掉镜头里的垫圈才能在18mm infinity focus,就是改小了
flange.其他的f镜头是不是也会同样问题 还是不一定? 转接头卖家声称 可以infinity
focus,别人还推荐的.觉得这个长度应该很好控制住的,国内的制作水平不至于吧 |
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s********e
发帖数: 2783 | 27 The Spanish site DSLRmagazine interviewed Akihiro Egawa and Makoto Kanai
from Sony. And here are some of the key info:
1) Asked why the new FE lenses are so big the answer was that if you want
goo optical quality you cannot reduce the size of the lenses.
2) The interviewer asked if the short flange distance and the limited E-
mount diameter is a major limitation for Sony lens designers. The answer was
no, for small focal distance lenses this kind of design helps us. The
opposite occurs with the ... 阅读全帖 |
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m*******n
发帖数: 519 | 28 刚刚收到寄回D7000相机和35mm DX 1.8g镜头，尼康列了下面这些：
-Repaired Mirror Box
-Adjusted Mirror Angle
-Adjusted Auto Focus Operation
-General Check & Clean
-Checked Body Flange Back
-Checked Communication
-Checked Battery Drain
-Clean CCD
镜头就是checked and cleaned。贴了两张图前后比较一下，都是AF-S，中心点对焦，
室内灯光，对焦好很多。just FYI. |
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y*b
发帖数: 3190 | 29 Innovative Sony multilayer sensor patent shows how to get rid of corner
issues.
“The short E-mount flange distance has one “drawback”. Lenses have to be
larger to correct the incident angle at the corner which usually causes
heavy color shifting, huge vignetting and loss of sharpness. That’s why
Voigtlander redesigned the Heliar 15mm III lens (here on eBay). And the new
design makes the new lenses twice as big as the predecessor.
Sony seems to have acknowledged that there is an issue to be solve... 阅读全帖 |
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y*b
发帖数: 3190 | 30 zz from SAR
"Ilovehatephoto interviewed Zeiss managers and got those interesting answers:
1) About future FE lenses: “we can expect about 5 new Full-Frame E-mount
lenses, including 2 to 3 new ones in 2016.”
2) About macro and tilt shift lenses: “We are well aware of the lack of
specialty lenses in the FE-mount system and we are working on developing
some for this system. ”
3) About the Batis backorder issue: “We have to admit that we have been
surprised by how popular the A7 markII series (A7II,... 阅读全帖 |
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e**n
发帖数: 5876 | 31 gx85大小和A6500差不多, 防抖做的好多了. 我看就是因为当初nex一代机, 非要追求
超薄机身的卖点, 搞了个18mm flange distance. 结果现在5轴防抖机构塞不进去. 市
场部要求硬塞, 工程部只好塞个缩水的. 然后市场部就使劲吹 |
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e**n
发帖数: 5876 | 32 gx85大小和A6500差不多, 防抖做的好多了. 我看就是因为当初nex一代机, 非要追求
超薄机身的卖点, 搞了个18mm flange distance. 结果现在5轴防抖机构塞不进去. 市
场部要求硬塞, 工程部只好塞个缩水的. 然后市场部就使劲吹 |
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h**x
发帖数: 628 | 33 这个视频恰好印证了DXOMARK我上面的贴图。你仔细看看评论：
Tony any insights as to WHY the canon lens is less sharp adapted? Is flange
distance wrong on adapter or are canon lenses engineered for hitting a
specific Canon style sensor glass? I'd really like a tech insight into this
issue and what it truly means.
同机比较只有35端S是稍稍软，但这点对超广镜头不重要。
但S家1635广角端更好， 16mm边角比C的好太多太多，这差距比C家自己的红圈与伪红圈
之间差距更大。这种边角表现在高像素机上是不合格的。
结论： C的1635f4依然是个伪红圈，无论跟S的1635f4比还是跟家1635f2.8II真红圈去
比。
跨机比较，作者用1/6，f4参数拍室内。这不够严谨。 |
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b*****e
发帖数: 5133 | 34 其实正好抵消，同样曝光快门不变的话，FF用f/5.6拍出MFT f/2.8一样景深ISO就要翻
两翻，但理论上MFT ISO 100的噪点和FF ISO 400一个水平。
如果完全等效的话，让FF 24-70和MFT 12-35一个等效水平根本就不需要造那么大。现
在整那么大就可以拍MFT拍不出的景深和低噪。FF和MFT都是为自身画幅优化设计镜头，
自己取舍用哪个系统，FF上单反镜头设计需要考虑flange distance限制体积会稍大，
但看看索尼无反几个f/2.8头的尺寸也没省下多少。画幅尺寸和镜头大小都不可能既占
便宜又不吃亏的。比较悲催的其实是残幅机还用全幅镜头的。
[在 egon (schiele) 的大作中提到：]
:等效的只有景深, f2.8就是f2.8. 如何你非要f2.8等效f5.6的话, 那么同时ff的高感
就没有优势了. |
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y*b
发帖数: 3190 | 35 zz from nikon rumors:
"A quick update on my last post about the rumored new full-frame mirrorless
Z-mount from Nikon: the measurements I reported caused some confusion in the
comments section - my understanding is that the external diameter of 49mm
is the actual mount opening, the entire external diameter of the mount is
going to be 65.4mm (just received this update):
Mount diameter (opening): 49mm
Total diameter of mount: 65.4mm
Flange focal distance: 16mm
The top graph by Eric Calabros shows a... 阅读全帖 |
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y*b
发帖数: 3190 | 36 zz from CW
"Is this Canon patent application describing a mirrorless system camera with
an EVF and IBIS? We tend to believe it does.
Canon patent application US20180041705 refers clearly to image stabilisation
“in camera”. Moreover, as one reader noted, it looks like it will use a
current Canon mount, since it doesn’t have the short flange a mirrorless
must would have. Furthermore, there is no mirror in the images. It appears
that an electronic viewfinder is placed where usually the pentaprism i... 阅读全帖 |
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a******d
发帖数: 955 | 37 佳能聪明啊，溅射和大师们留在佳能的原因就是镜头啊，如果ef口不能用了，很多人说
不定索性灭门转索了
反观尼康，还要给午饭搞什么新的口，不是逼咱们灭门嘛
话说回来flange也不是大问题了，现在午饭存在的价值已经远远不止轻便这一点了，所
以做重点也无所谓了 |
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t******8
发帖数: 2803 | 38 还在草稿纸上呢。只是个rumor，好像刚申请专利。转接同样容易，好像flange
distance比E口还小。 |
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t******8
发帖数: 2803 | 39 还在草稿纸上呢。只是个rumor，好像刚申请专利。转接同样容易，好像flange
distance比E口还小。 |
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p******s
发帖数: 938 | 40 Try Chorus Effect, very very beautiful
Flange is interesting...
and a proper sue of Wah could be so cooll... |
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f*******k
发帖数: 2187 | 42 这种女人很多啊，尤其在北美，咱们说是不是。
当年老公做穷博士博士后的时候，苦哈哈的跟着来，跟老黑合作个两房公寓。平时老公
刷试管，自己学英语学会计学EXCEL，然后做个兼职一个月赚八九百刀。还要把老公奖
学金都掌控起来。看着老公一百个不顺眼，没事上网招蜂引蝶，拿老公钱跟野男人幽会。
后来，博士后出头了，去了药厂、去了FLANG、去了花儿街，或者做教职的发了各种论
文，被香港中东新加坡撒钱大学给要了去了，熬到四十来岁，都年薪四五十万刀了。又
或者海归创业赚大钱了。这时候又整天在外边拿老公炫耀了。
这种人，你们说多不多。。。 |
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x*******i
发帖数: 819 | 43 可以最下面（里面）加一圈rabbit fence. 因为主要是防狗，所以在合同里最好说好要
多粗的铁丝，网眼多大，还要说好深埋至少6"或者你想要的深度. 上面有一尺多，他们
会给订到你的木fence上。我当时就因为这些没写到合同里，施工的时候有纠纷了。工
人偷懒，说兔子挖不了这么深。还说什么“相信我"。我相信他才怪了。最后打电话给
salesman才解决。（最好施工时看着，不然工人有可能偷懒，埋好了你也不知道。）我
当时要求挖好沟先别埋，等我认可了才能埋。有几处不够深都挑出来了。
这里有一段rabbit fence怎么埋的介绍。
To address rabbits' digging behavior, be sure to ground your fence deeply
into the ground. If your stakes will be about 2" wide, you'll want to form a
perimeter by digging a trench about 6" deep and 8" wide. Then, on the
inside of t... 阅读全帖 |
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L****o
发帖数: 1642 | 44 2012年Tracy Smith以诗集《Life on Mars》（《火星生活》）获得美国普利策诗歌奖
，这本诗集“大胆、巧妙，将读者带上宇宙，并让他们真实感受到了快乐与苦痛。”
看到shot写的《慧星》、《宇宙长城》，想起了这个，贴几首里面的诗吧。
《The Weather in Space》
Is God being or pure force? The wind
Or what commands it? When our lives slow
And we can hold all that we love, it sprawls
In our laps like a gangly doll. When the storm
Kicks up and nothing is ours, we go chasing
After all we’re certain to lose, so alive—
Faces radiant with panic
《太空里的天气》
译/Lihebo
上帝是存在还是纯粹的力？风
还是驾驭它的东西？当我们的生活缓慢
并拥有所爱的一切，它四... 阅读全帖 |
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J*******r
发帖数: 348 | 45 PL是plate，B.F.可能是both flange?~~ |
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i******y
发帖数: 48 | 46 PL is the abbreviation of plate for sure.
BF could be bottom flange of a w shape. |
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i******y
发帖数: 48 | 47 PL is the abbreviation of plate for sure.
BF could be bottom flange of a w shape. |
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E*******d
发帖数: 495 | 48 你那个 6"x6"x1/8" 明显是尺寸和厚度，所以 PL 应该是 Plate 的缩写。至于 B.F.
就要具体情况具体分析了。可能是 both face, 但一般用 each face (E.F.). Bottom
一般用 Bot. , Flange 一般用 Flg. |
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a*******l
发帖数: 2353 | 49 Beam to column connection
Shear only connection
Double angle on beam web.
Bolted on both beam web and column flange.
设计bolts只考虑剪力,因为梁翼板没有和柱焊接不能形成有效的力矩.
但是,通常我们说shear only,简支梁端的连接,基本上free of rotation.
考虑极端情况,角钢长度和梁深一样,根据设计可以只用两个bolt,上下各一个关于中性
轴对称, 如何free rotation? 如果不能自由转动,岂不是可以承担弯矩,可以承担多少
? 最大为梁腹板屈服?
LRFD设计验算Shear, Bearing, Block shear (shear rupture)中,哪一项包含了上述内
容?
我是不是想得太奇怪了. |
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