题干
The 21stWinter Olympic Games were successfully held in_____city of Vancouver，_____ big city in Canada．
A：a；a
B：the；a
C：a；the
D：the；the
答案(点此获取答案解析）
B
A：a；a
B：the；a
C：a；the
D：the；the
作中不需要做的是