Suppose the preparatory work should not be completed.

　　準備工作完成不了，那可怎么辦？

　　Lenin did a great deal of the preparatory work for this conference.

　　列寧為這次會(huì )議作了大量的準備工作。

　　A rigorous and comprehensive approach requires some preparatory work.

　　應用嚴格的、綜合的方法需要作某些準備工作。