题目

新宁脐橙是湖南邵阳的特产，如图所示，重为6N的脐橙，从树上落下的过程中，同时受到重力和空气阻力的作用。对于脐橙所受合力的大小和方向，以下说法中正确的是（ ）A. 大于6N，方向向上B. 小于6N，方向向下C. 大于6N，方向向下D. 小于6N，方向向上 答案：【答案】B【解析】根据脐橙受到重力和空气阻力作用，并且二力方向相反，结合同一直线反方向二力合力的大小等于二力之差，即可知道脐橙所受合力的大小和方向。根据题意知道，脐橙从树上落下的过程中，同时受到重力和空气阻力的作用，且二力方向相反，由于二力合力的大小等于二力之差，故合We were driving on the right road when, all of a sudden, a black car pulled out of a parking space right in front of us. My taxi driver stepped on his brake, skidded(打滑), and missed the black car’s back end by just inches! The driver of the black car, who almost caused a major accident, turned his head angrily and started shouting bad words at us. My taxi driver just smiled and waved at the guy. I mean, my taxi driver was friendly. So, I said, “Why did you just do that? This guy almost ruined your car and sent us to hospital!” And the following is what my taxi driver told me, which I now call “the law of the Garbage Truck”. “Many people are like garbage(垃圾) trucks. They run around full of garbage, full of anger, and full of disappointment. As their garbage piles up, they need a place to dump(倾卸)it. And if you let them, they dump it on you. When someone wants to dump on you, don’t take it personally. Just smile, wave, wish him well, and move on. Believe me. You’ll be happier.” So this is “The Law of the Garbage Truck”. I started thinking: How often do I let “Garbage Trucks” run right over me? And how often do I take their garbage and spread it to other people at work, at home, or on the streets? It was then that I said, “I’m not going to do it any more.” I began to see “Garbage Trucks”. I see the load they’re carrying. I see them coming to drop it off. And like my taxi driver, I don’t make it a personal thing; I just smile, wave, and move on. Good leaders know they have to be ready for their next meeting. Good parents know that they have to welcome their children home from school with hugs and kisses. What about you? The mark of a successful person is how quickly he can get back his focus on what’s important. 1.Who acted like a garbage truck in the accident described in the first two paragraphs? A．The author. B．The driver of the black car. C．The taxi driver. D．Both drivers. 2.The reason why the taxi driver just smiled and waved at the guy is that ______. A．the black car was full of garbage B．the driver of the black car didn’t cause any damage to the taxi C．the taxi driver didn’t want his mood ruined D．the driver of the black car was angry and the taxi driver felt a little frightened 3.The underlined part “the load” in Paragraph 5 refers to _____. A．waste materials B．excitement C．new products D．bad mood 4.What is the main idea of the last paragraph? A．Always be kind and hardworking. B．Try to be good leaders as well as good parents. C．Ignore unpleasantness and stick to(坚持) your tasks. D．Do things quickly so as to be ready for the next.