20．He was highly respected 　　　　　what he had done for the flooded area．

A．because　　 　　　 B．because of　 　　　 C．in spite of　 　　　　 D．as a result

19．　　　 　made people worried is 　　　　the environment is being polluted seriously．

A．What；that　 　　　 B．That；that　 　　　 C．What；how 　　　 D．Which；that

18．Only after my friend came 　　　　　．

A．did the computer repair　　　 　　　　　　 B．he repaired the computer

C．was the computer repaired　　　 　　　 D．the computer was repaired

17．My MP4 player isn't in my bag．Where　　　　 I have put it？

A．can　　　 　　　　 B．must　　　 　　　 C．should　　 　　　　　 D．would