单项选择题The ircrft bse is protected with specilly designed shelters which re built to nd ir ttcks.lunchB withstndC contestD contend
单项选择题My classmate( )( )( )a lot of good deeds for others.has been doneB. didC. was doingD. had done
单项选择题( )( )( ) in this light, the matter is not as serious as people generally suppose.To seeB. SeenC. SeeingD. Being seen
单项选择题The number of teachers in this school()unknown.
A.are B.is being C.is D.are being
单项选择题A number of paintings in the castle are believed( )( )( )in a fire.being destroyedB. having been destroyedC. to be destroyedD. to have been destroyed
单项选择题Middle school boys( )( )( )not to smoke.
单项选择题The class ( )( )( ) over, we had a ( )( )( )discussion.
单项选择题We specialize ( ) the exportation of Chinese light industrial products.
单项选择题The method is ( ) cheaper and safer.
单项选择题Which of the following choices is not the compulsory component of business letters?