She examined the door again for fear that a thief (should) come in.
He goes closer to the man so that he can hear him clearer. 在so that, in order that引导的目的状语从句中，从句的谓语为：can/could/may/might/will/would/should+do.
动词wish后的宾语从句中，若要表示与现在事实相反的愿望，从句谓语用一般过去时或过去进行时；若表示与过去事实相反的愿望，从句谓语用would/could +have+过去分词或者过去完成时had done;若要表示将来没有把握或不太可能实现的愿望，用would/could+动词原形。
动词desire, direct,arrange,urge后的宾语从句中，从句谓语为should+动词原形，should可以省略。
It is (high/about)time that +主语+动词过去式/should+do(should不能省略）