The Smiths ______ many places of interest since two years ago．（ ）
A．visitB．have visited
C．visited
﹣What's your _____to English learning，Lin Tao？
﹣I think watching English movies is helpful．（ ）
A．placeB．ageC．timeD．secret
﹣What have you learnt after three year's study in China，Maria？
﹣I was taught ____knowledge _____good manners．（ ）
A．either； orB．not only； but also
C．neither； norD．not； but
﹣Teamwork is very important in a football match．
﹣I think so．_______（ ）
A．The early bird catches the worm．
B．Every dog has its day．
C．One tree can't make a forest．
D．Everything comes to him who waits
﹣Excuse me，can you tell me ______？
﹣Sorry，I am too busy now．Why not search the Internet for information？（ ）
A．how does smog （雾霾） come into being
B．where the national space station lies
C．why are tigers becoming fewer now
D．how many years did the Qin empire last
﹣It's said that nuclear power will be used to produce electricity in Xianning．
﹣However，nuclear power _____be very dangerous．（ ）
A．canB．needC．mustD．should