题目

如图所示，小车M在恒力F作用下，沿水平地面做直线运动，由此可判断( ) A . 若地面光滑，则小车一定受三个力作用 B . 若地面粗糙，小车也可以不受摩擦力作用 C . 若小车做匀速运动，则小车一定受四个力的作用 D . 若小车做匀速运动，则小车可能受三个力的作用 答案：B,CTravellingI guess you must know the West Lake. It's the most beautiful lake I've visited. When I got there this March, I took photos and went boating there. It had so many great sights (景象) that I didn't want to leave.-NancySanya is a beautiful place with great beaches. I flew there last winter. It was warm, so I went swimming and had a sunbath.(日光浴) there. I also tasted delicious seafood. I really enjoyed myself there.-PeterWhen I got to Xishuangbanna with my friends last year, we went to visit the primeval (原始的)forest. There were tall trees, colorful leaves, wild animals and clean rivers. They were all magic to us. We even camped near a river there. What an exciting experience!-LindaHave you seen steep (险峻的) mountains before? Yes, I have. Last summer my parents and I visited Mount Hua, in Shanxi Province. It took us almost ten hours to climb up to the top of Mount Hua. Though it was summer, we felt cool.-Jacky根据短文内容，选择最佳答案。1.When did Nancy visit the West Lake?A.In spring B.In summer C.In autumn D.In winter2.How did Peter like his trip to Sanya?A.Tiring B.Enjoyable C.Surprising D.Boring3.What did Linda do during her trip?A.She took photos B.She went campingC.She had a sunbath. D.She climbed mountains.4.Who went to Mount Hua with Jacky last summer?A.Nobody but himself B.His sisterC.His friend D.His parents5.What can we know from the passage?A.Nancy ate seafood during her trip. B.Sanya has many beautiful mountains.C.Linda went to Xishuangbanna with her parents. D.Jacky thought that Mount Hua was steep.