题目

如图（不计绳重摩擦，且动滑轮重小于物重），用它们分别将重相同的甲、乙两物体匀速提升相同的高度，所用的拉力分别为F甲、F乙，它们的机械效率分别为η甲、η乙。则F甲_____F乙 η甲_____η乙（选填“＞”、“＜”或“＝”） 答案：＞ 、＜解析:略阅读理解。A: Do you like to play ball games, Peter? B: Yes, I do. A: Basketball, football or volleyball? B: I like to play football. A: Who likes to play basketball in your class? B: Tom does. A: Do you like to play volleyball, Joan? C: Yes, I do. I like to play volleyball very much. A: Let's play volleyball. C: That sounds fun. A: Do you have a volleyball? C: Yes, I do. A: Now let's go and play it. 1. Who likes to play football?    __________________________________________2. Does Tom like to play basketball?     __________________________________________3. What does Joan like to play?    __________________________________________4. Who has a volleyball?     __________________________________________5. Do Peter and Joan like sports?     __________________________________________