Three hundred firemen raced to the hotel after a smoke detector(检测器)_____ the alarm soon after midnight.
| A．set out | B．set off | C．give away | D．give off |
. ____ of the land in my hometown ____ covered with trees and grass.
| A．Two-fifths; is | B．Two-fifth; are | C．Two-fifth; is | D．Two-fifths; are |
. It is difficult for us to _________ a conversation with so much noise around us. 
| A．communicate with | B．carry on | C．set up | D．bring  up |
I failed again in the examination and only then _____ how much time I had wasted. 
| A．I realized | B．I had realized | C．did I realize | D．had I realized |
She knows so much about England. She ________ there before. 
| A．must be | B．must have been | C．must live | D．must have lived in |
—How do you like your new neighbour?
—She is _________, but her appearance is a bit_________. 
| A．interesting; disappointed | B．interested; disappointed |
C．interesting; disappointing | D．interested; disappointing |