20．All these changes will lead to a strong and powerful China, _______ that can surprise the whole world.

　　　 A．what　　　　　 B．which　　 　　　　 C．the one　 　　　　　　 D．one

19．Try to_________ at least half an hour each day for learning new vocabulary, and you’ll know more words.

　　　 A．set aside　 　　　　 B．take up　 　　　　　　 C．put away　 　　　　 D．go about