I __________ a lot of beer when I visited Qingdao.
A. was drinking
B. had drunk
C. drank
The Bund __________ Shanghai is often crowded __________ both locals and tourists.
A. with; in
B. of; for
C. of; with
The river __________ very clean ten years ago, but now it is polluted.
A. was used to be
B. was
C. is
Canada is __________ largest country in the world by total area.
A. the second
B. a second
C. the two