【正确答案】正确答案：Some people suggest that the project not be started until all preparations have been made．

【答案解析】解析：(表示建议时，可用advise，suggest，propose，recommend。有这些词时，需要用到虚拟语气。且无论主句谓语动词为何种时态，从句的谓语动词都用：should+do。should可以省略。)