It is recommended that the project not be started until all the preparations have been ma

问题补充：

It is recommended that the project not be started until all the preparations have been made.

A. must

B. can

C. need

D. should

答案：

A. must

B. can

C. need

(答案→)D. should

解析：考察虚拟语气。动词recommend后面的宾语从句要使用虚拟语气should+动词原形；其中的should可以省略。句意：人们建议知道所有的准备都做好以后才开始这项计划。故D正确。