20．She'll never forget her stay there _________ she found her son who had gone missing two years before．

A．that　　　　　　　　 　　　 B．which　　　　　　　 　　　 C．where　　　　　　　 　　　 D．when

19．My uncle's house in the downtown area in much smaller than ours，but it is twice _______ expensive．

A．as　　　　　　　　　 　　　 B．so　　　　　　　　　 　　　 C．too　　　　　　　　　 　　　 D．very

18．--You speak very good French!

--Thanks．I _________ French is Sichuan University for four years．

A．studied　　　　　　　　　 B．study　　　　　　　 C．was studying　　　　　 　　　 D．had studied

17．The teacher together with the students _________ discussing Reading Skills that _________ newly published in America．

A．are；were　　　　 　　　 B．is；were　　　　　 　　　 C．are；was　　　　 　　　 D．is；was

16．Not until I came last night _________ to bed．

A．Mum did go　　 B．did Mum go　　　　　　　　 C．went Mum 　　 　　　 D．Mum went

15．--Why don't we choose that road to save time?

--The bridge to it _________．

A．has repaired 　　　　　 B．is repaired　　　　　　　 C．is being repaired　　　 D．will be repaired