19. A. The terrorists broke the World Trade Center into pieces in September 11 ,2001.

   B. The terrorists               the World Trade Center in September 11,2001.

(   ) 15. The group sat there in        at first,then slowly discussion began.

   A. common   B. fact     C.half      D.silence

19.at,doing,last,o’clock,morning,nine,Sunday,you,were,what,(？) 

18.began,heavily,home,I,it,rain,to,walking,was,when,(.) 

20.A heavy storm happened last week.

我家附近发生了一起严重车祸。

17.When it began to rain,Ben was helping his mom make dinner.

你打电话时，我正在看电视。

(   ) 12. Seeing so many teachers,she was        at first,but soon she relaxed herself.

   A. afraid     B. nervous     C. shocked   D. scared

(   ) 12. The weather report told the people at sea to prepare for the coming typhoon (台风)          

   A. rain   B. snow    C.storm   D. wind

17.a,called,hot,I,shower,taking,you,was,when,(.)