It's four o'clock in the afternoon. The boys _at the pool.[ ]A. is swimmingB. are swimming
A. is swimmingB. are swimmingC. swim
题目简介
It's four o'clock in the afternoon. The boys _at the pool.[ ]A. is swimmingB. are swimming
题目详情
A. is swimming
B. are swimming
C. swim
答案