题目

下列有关细胞生命历程的说法正确的是（ ） A . 细胞生长：核糖体的数量增加，物质运输效率升高 B . 细胞分化：核遗传物质没有发生改变，但tRNA种类有变化 C . 细胞癌变：细胞膜上的糖蛋白减少，多个基因发生突变 D . 细胞凋亡：相关基因活动加强，不利于个体的生长发育 答案：CWe have all experienced days when everything goes wrong．A day may begin well enough，but suddenly everything seems to get out of control．It seems as if a single unimportant event may cause a number of things to happen．Let us suppose that you are preparing a meal and keeping an eye on the baby at the same time．The telephone rings and this means your troubles are beginning．While you are on the phone，the baby pulls the table-cloth off the table，destroying your half-prepared meal．You hang up hurriedly and attend to your baby．Meanwhile，the meal gets burnt．As if this were not enough to bring you to tears，your husband arrives,unexpectedly bringing three guests to dinner． Things can go wrong on a number of people on the road. During the rush hour one evening two cars hit each other and both drivers began to argue．The woman driver behind the two cars happened to be a learner．She suddenly got into a panic(恐慌)and stopped her car．This made the driver following her stop suddenly．His wife was sitting beside him holding a large cake．As she was thrown forward，the cake went right through the window and landed on the road．Seeing a cake flying through the air，a truck-driver had to stop his truck all of a sudden．The truck was carrying empty beer bottles and hundreds of them slid off the back of the truck on the road．This led to yet another angry argument．Meanwhile，the traffic piled up behind．It took the police nearly an hour to get the traffic on the move again．In the meanwhile，the truck-driver had to sweep up hundreds of broken bottles.Only two dogs were enjoying themselves from the accident，for they were happily having what was left of the cake．It was just one of those days! 1.In the writer’s opinion         . A．accidents may happen anytime B．troubles always come in groups C．a small matter may cause great trouble D．anyone may have trouble any day 2.What did the police do after the accident? A．They helped the driver clean up the road． B．They helped the drivers to go on with their journey． C．They tried to stop the people from arguing． D．They would find out who should be responsible for(有责任的)the accident． 3.When the telephone rings        . A．you’d better have your baby a little distant from your table before going to answer the phone B．you’d better just let it ring all the way C．you should never go to answer it in a hurry D．you should answer it right away 4.From the story we can see_________． A．some drivers are too careless B．such accidents are rather strange C．such accidents are very common D．we don’t know why such accidents happen