题目

They ______ ideas with each other at the meeting.A.had a great time exchangingB.had a good time exchangesC.had fun to exchangeD.enjoyed themselves exchanges 答案：【答案】A【解析】句意:在会议上，他们彼此交换意见，觉得很愉快。考查动词短语。have a good/great time = enjoy oneself = have fun 玩得很开心。根据句意可知本句的时态为一般过去式，谓语动词用过去式，且此处省略介词in，后接动名词短语，作介词的宾语。exchange动词，交换，此处用exchanging。故选A。计算：（1）ab+1+2ab+1-3a1+b（2）x2+1x-6•x2-36x3+x．