5. 某些名词后的表语从句和同位语从句中谓语动词要用虚拟语气
　　在一些名词后面的表语从句和同位语从句中，谓语动词要用虚拟语气。这时，谓语动词用动词原形或should 动词原形。这类名词一般表示命令，要求，决定，建议，主张等概念，主要有：advice, idea, instruction, motion, order, plan, proposal, recommendation, request, requirement, suggestion,等。

　　My suggestion is that we (should) send for a doctor immediately.
　　He gave the order that they (should) do the experiment again.