问题补充:
—I called you at 4:50 yesterday afternoon, but no one answered.
—Sorry. Iwith my friends at that time.
A. swam
B. swim
C. was swimming
D. will swim
答案:
A. swam
B. swim
(答案→)C. was swimming
D. will swim
解析:句意:昨天下文四点五十分我给你大电话了,但是没有人接。——抱歉,那时我正在和我的朋友游泳。结合语境可知下文描述的是过去某时正在进行的动作,故用过去进行时态。选C。