虚拟语气中的should是什么时候都能省略吗?还是只有在表示建议命令要求是中,should可省略?

虚拟语气中的should是什么时候都能省略吗?还是只有在表示建议命令要求是中,should可省略?

不是
再问： 那是什么呢？
再答： 1. 在表示建议,要求,命令,想法的动词后的从句里, 用should + 动词原形, should 可以省略. 如 advise, agree, command, decide, demand, determine, grant, indicate, insist, order, prefer, propose, request, require, stipulate, suggest, urge, vote.常考到的是: suggest, advise, demand, require, propose, insist, order, request. His doctor suggested that he (should) take short leave of absence. The author proposed that TV (should) be turned off at least one hour every day. 2. 在表示建议,要求,命令,想法的名词后的从句里, 用should + 动词原形, should可以省略. 如 advice, decision,agreement, command, decree, demand, determination, indication, insistence, order, preference, proposal, request, requirement, stipulation etc. It was Bill’s suggestion that everyone (should) have a map. His suggestion was that everyone (should) have a map. He gave us a suggestion that everyone (should) have a map. 3. 在It is/was +形容词后的that 从句中用should的结构, should 可以省略. 这类形容词常见的有: advisable, anxious, compulsory, crucial, desirable, eager, essential, fitting, imperative(绝对必要), impossible, improper, important, natural, necessary, obligatory, possible, preferable, probable, recommended, urgent, vital etc. It‘s natural that she (should) do so. It is essential that we (should) tell her the news. 4. 在 lest 和 for fear that(以免),in case(以防)从句中用should, should 可以省略. She walked quietly lest she (should) wake up her roommates. Have your gun ready in case we should need it.
再问： 如果是if条件句中有should是不是就不能省略了？
再答： 当然，此时省略if且提前should,后面倒装