1·As the infection worsens, the nail bed may retract, and nails may thicken and crumble.
随着感染的加重，甲床会缩回，然后指甲变得越来越厚，最后碎裂。
2·A ladybug can retract its head into its body.
瓢虫可以将自己的头缩回到躯体中去。
3·Some methods use impact to retract the locking bolt, most of which are destructive.
个别方法利用冲击力来使锁闸缩回，但大多数都会令材料解体。
1·Secondary actions, such as “Back” and “Cancel, ” enable users to retract data that they have entered.
次要操作，诸如“后退”和“取消”，可以让用户撤消已经输入的数据。
2·Similarly, if you retract permissions with - (minus), it disables certain permissions but otherwise leaves the status quo.
与之类似，如果使用-(减号)撤消权限，它将会禁用某些权限，但不会修改其他的权限。
3·Q . Is there any way to retract a candidate submission or re submission?
是否有方法撤消一个候选点的上报和第二次上报吗?。
4·The accused refused to retract.
那被告拒不撤消。
1·In March his aides let slip that he would make a big announcement during a stop at the state Capitol in Atlanta, Georgia, only to retract the whole plan for reasons that still remain opaque.
三月份他的助手们无意中透露过，他将会在佐治亚州亚特兰大州议会厅逗留期间做一重大宣布：由于各种仍保密的原因要取消整个竞选计划。
1·Using this result we prove in this paper that every contractible polyhedron is an absolute retract.
借助于这一结果，本文证明了每一个可缩多面体均是个绝对收缩核。