题目

三峡水电站是利用大坝把水拦住，使水位变高，从上游流下的水带动发电机发电这说明被大坝拦在上游的水具有 （ ） A . 弹性势能 B . 重力势能 C . 动能 D . 以上三种能都有 答案：BMany people love going on a trip by plane , but an airport is usually far from the city . You have to arrive there and wait for hours for the plane to take off and it is often late . You can't open the window .You can't choose the food .Planes are fast ,but it takes hours to get out of the airport and into the city . I like travelling by train .I think trains are safe . Train stations are usually in cities . when you are late for a train , you can catch another one . You can walk around in the train and open the windows . You can see many interesing things on your way . I know it takes a little more time . I also like cars . You can start your trip when you want to . and you don't need to get to a station . You can carry many things with you too . But sometimes there are many cars on the road1.Many people like travelling by plane because _______.A.it is slowB.you can open the windowC.it is fastD.the airport is fay from the city2.What does "take off " mean ?A.达到B.起飞C.降落D.脱掉3.If you want to take many things with you , you would like to take _______.A.a busB.a trainC.a planeD.a car4.What is the disadvantge of the car ?A.You needn't go to the stationB.You can start your trip when you want toC.There are too many cars on the roadD.You can see many interesting things5.which sentence about the writer is TRUE?A.He likes taking a plane because it takes a lot of time to go to the cityB.He likes taking a train because train stations are usually in citiesC.He likes taking a bus because he can drive itD.He likes taking a plane because it is fast