题目

下列有关生物学实验的叙述中，正确的是（   ） A．在观察根尖分生组织细胞的有丝分裂实验中，将解离、漂洗、染色的洋葱根尖置于载玻片上，盖上盖玻片即可在显微镜下观察。 B．在低温诱导植物染色体数目的变化的实验中，剪取诱导处理的根尖，立即放入解离液中解离，然后漂洗、染色、制片。 C．观察线粒体，用新鲜的藓类叶代替口腔上皮细胞，效果较佳 D．选用紫色洋葱鳞片叶表皮细胞观察到质壁分离现象时，观察不到染色体In the city of Chicago I met a man I will never forget. He drove a bus that ran from downtown to the edge of the city. Each night I watched him. As the passengers got on the bus, he smiled at each one. It was fun to see how many passengers forgot their troubles and smiled back.There was one passenger, I noticed, that had never smiled back. He usually coughed roughly through his mustache (胡子) as he got on the bus. And he never covered his mouth. But that wasn’t enough to stop the bus driver’s smile. He gave the man with the mustache and the rough cough his biggest smile.The man with the mustache never seemed to see that smile. He would sit on the edge of his seat and complained about the way that the bus driver was driving. He only complained for a short time, but he spoke loudly enough so everybody could hear. It was enough to make me sick. But the driver never said a word. He just went on smiling at passengers as they got on the bus.I wanted to get to know this bus driver better. One night I stayed on the bus to the end of the line. I asked the driver, “Why don’t you throw that man with the mustache out of the bus?” The bus driver looked at me and gave me one of his famous smiles. “I don’t care about that,” he said. “Let me tell you about my friend’s dog. The man next door to me has a dog. Every time the moon shines, the dog barks (狗叫) and barks all night.” “Well, what about the dog and the moon?” I asked. “Oh, the moon keeps on shining,” he said.小题1:The first paragraph mainly tells us           .A．the writer was interested in the bus driverB．there was a bus from downtown to ChicagoC．each night the writer watched the driver drivingD．it was fun for the driver to see passengers smiling小题2:What did the man with a mustache usually do on the bus?A．He never said a word.B．He talked loudly to others.C．He complained about the way to the city.D．He complained that the driver didn’t drive well.小题3:The writer stayed on the bus to the end of the line because he wanted             .A．to listen to an interesting storyB．to know more about the driverC．to ask about the dog and the moonD．to ask the driver to throw the man out小题4:What does the passage imply (暗示)?A．Bus drivers should smile at passengers.B．It’s no good to be rough to others.C．We should learn to be polite.D．We should learn to be generous（宽宏大量的）.