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- The membrane envelope isolates the contents from the surrounding cytoplasm. 这些小泡依赖封闭的外膜得以与细胞质相独立而存在。
- The younger bacteroid was elliptic and had a similar nucleus region in cell. The normal bacteroid had an intact membrane envelope and PHB granules. 幼年美菌体为椭圆形，里面有个拟核区，正常类菌体有完整的周膜和PHB颗粒。
- One outer membrane envelops both amniotic sacs. 两个羊膜囊由一个外膜层包裹。
- A. Identical Twins Fetuses are of the same sex and share one placenta. One outer membrane envelops both amniotic sacs. 同卵双胞胎性别相同，并共享一个胎盘。两个羊膜囊由一个外膜层包裹。
- Have you stuck down the back of the envelope? 信封背面开口处贴牢了吗？
- Cross-cuts of cilia showing the typical 9X2 +2 arrangement of microtubules within the cytoplasm ( ring of 9 doublets plus 2 single microtubules in the center). The cell membrane envelopes each cilium. 纤毛横切面显示了典型的9X2+2微管排列结构（环绕周边的9组二联微管加中间两条单独的微管。胞膜覆盖在纤毛表面。
- He steamed the stamp off the envelope. 他用蒸汽把信封上的邮票揭下来。
- He glued a stamp onto the envelope. 他把邮票贴在信封上。
- As he picked up the envelope, a key dropped out. 他拣起信封时，一把钥匙掉了出来。
- As she picked up the envelope, a key dropped out. 她拾起信封时，一把钥匙掉了出来。
- Put a stamp on the envelope, will you? 在信封上贴张邮票，好吗？
- He stuck a stamp on the envelope. 他在信封上贴上邮票。
- She opened the envelope with her fingertips. 她用指尖弄开了信封。
- The envelope's seal was torn open. 信封封缄被撕开了。
- The (flap of the) envelope was unstuck. 信封(的封口)没粘住。
- There are several enclosures in the envelope. 信封内装有几份附件。
- A thin layer of bone, membrane, or other tissue. 骨骼、粘膜或其它组织的薄层
- An envelope or wrapper for mail. 封套，信封为邮寄而制的信封或封套
- A good way to remove a stamp from an envelope is to soak it off. 从信封上取下邮票的一个好办法就是用水把它泡下来。
- I enclose a stamped addressed envelope for your reply. 兹附上贴有邮票并写好地址的回邮信封。
