题干

如图所示为体育场内足球赛的场景,小刚和小亮运用所学物理知识对比赛中的一些现象进行分析,下列说法中全部正确的一组是(  )

①足球在上升过程中重力势能转化为动能

②踢出去的足球能继续向前飞行是由于惯性

③足球在空中飞行时受到重力和向前的推力

④足球在空中飞行过程中,运动状态发生改变

⑤空中飞行的足球,若它所受的力全部消失,它将立即落地

⑥踢球时脚感到疼是因为物体间力的作用是相互的

A:①③⑥

B:②③⑤

C:②④⑥

D:①②⑤

上一题 下一题 0.0难度 选择题 更新时间:2018-07-05 06:19:33

答案(点此获取答案解析)

C

同类题3

阅读理解

    A year ago, I paid no attention to English idioms, though my teacher emphasized (强调) the importance again and again. But soon, the importance of English idioms was shown in an amusing experience.

    One day, I happened to meet an Englishman on the road, and soon we began to talk. As I was talking about how I was studying English, the foreigner seemed to be astonished. Gently shaking his head, shrugging his shoulders, he said, “You don't say!” “You don't say!” I was puzzled. I thought, perhaps this is not an appropriate topic (适当的话题). “Well, I'd better change the topic.” So I said to him. “Well, shall we talk about the Great Wall? By the way, have you ever been there?” “Certainly, everyone back home will laugh at me if I leave China without seeing it. It was magnificent.” He was deep in thought when I began to talk like a tourist guide. “The Great Wall is one of the wonders in the world. We are very proud of it..” Soon I was interrupted again by his words: “You don't say!” I couldn't help asking, "Why do you ask me not to talk about it?" "Well, I didn't request you to do so, " he answered, greatly surprised. I said, "Didn't you say' you don't say?”Hearing this, the Englishman laughed to tears. He began to explain, “'You don't say' actually means 'really!' It is an expression of surprise. Perhaps you don't pay attention to English idioms.” Only then did I know I had made a fool of myself. Since then I have been more careful with idiomatic expressions. Remember: what the English teachers said is always right to us students.