问题 多选题

电灯悬挂在一根绳子下保持静止,则绳子对电灯的拉力(  )

A.跟电灯对绳子的拉力互相平衡

B.大小等于电灯所受的重力

C.是由绳子形变产生的

D.是由电灯形变产生的

答案

A、绳子对电灯的拉力与电灯对绳子的拉力是一对作用力和反作用力.故A错误.

B、电灯受重力和拉力平衡,拉力的大小等于电灯的重力.故B正确.

C、D、绳子对电灯的拉力是由绳子的形变产生的.故C正确,D错误.

故选BC.

阅读理解

One day while shopping in a small town in southern California,it was my misfortune to be approached by a clerk whose personality conflicted with mine. He seemed most unfriendly and not at all concerned about my intended purchase. I bought nothing,and marched angrily out of the store. My hostility(敌意) toward that clerk increased with each step.

On the outside,standing by the road,was a dark­skinned young man in his early twenties. His expressive brown eyes met and held mine,and in the next instant a beautiful, dazzling smile covered his face. I gave way immediately. The magnetic(磁力的) power of that smile dissolved all bitterness within me,and I found the muscles in my own face happily responding(回应).

“Beautiful day,isn't it?”I remarked,in passing. Then,I turned back.“I really owe you a debt of gratitude,”I said softly.

His smile deepened, but he made no attempt to answer.A Mexican woman and two men were standing nearby.The woman stepped forward and volunteered, "Sir, but he doesn't speak English.Do you want me to tell him something?" In that moment I felt transformed(改变).The young man's smile had made a big person of me.My friendliness and good will toward all mankind stood ten feet tall.

"Thank you?" The woman seemed slightly puzzled.

I gave her arm a friendly pat as I turned to leave."Just tell him that," I insisted."He'll understand.I am sure !"

Oh, what a smile can do! Although I have never seen that young man again, I shall never forget the lesson he taught me that morning.From that day on, I became smile-conscious, and I practice the art anywhere and everywhere, with everybody.

小题1:Why did the author leave the store angrily?

A.The clerk treated him unkindly.

B.He couldn't buy what he wanted.

C.The clerk didn't speak English.

D.The store's goods were too dear.小题2:By saying "I felt the muscles(肌肉) in my own face happily responding" (in Paragraph 2), the author means __.

A.he was still angry

B.he did not want to smile

C.he would thank the young man

D.he smiled back at the young man小题3:The author asked the woman to say "Thank you!" to the young man because the young man_____.

A.had helped the author before

B.taught the author how to smile

C.was a kind employee of the store

D.taught the author a valuable lesson小题4:In the passage, the author seems to suggest that we should __   ___.

A.be generous to strangers

B.practice smiling every day

C.smile at other people

D.help people in trouble

单项选择题