题目

–Tina, I called you last night but nobody answered. What were you doing?--I a bath.A.have B.have had C.will have D.was having 答案：【答案】D【解析】句意：Tina，我昨晚给你打电话了但是没有人接，你正在做什么？—我正在洗澡。A. have一般现在时；B. have had现在完成时；C. will have一般将来时；D. was having过去进行时，根据问句What were you doing?可知，应该用过去进行时回答，故答案选D。如图表示的是汽油机的_____冲程；在压缩冲程中，是通过____方式增加气体内能的。