题目

28.转基因抗虫棉可以有效地用于棉铃虫的防治。在大田中种植转基因抗虫棉的同时，间隔种植少量非转基因的棉花或其他作物，供棉铃虫取食。这种做法的主要目的是﹙    ﹚ A.维持棉田物种多样性 B.减缓棉铃虫抗性基因频率增加的速度 C．使食虫鸟有虫可食 D．维持棉田生态系统中的能量流动 答案：B29、Tom is ten years old，and he is a very lazy boy．He doesn’t like doing any work．He has to go to school，but he doesn’t study（学习）hard there and does as little work as possible（可能的）．His father and mother are doctors and they hope that their son also become a doctor in the future（将来）．But one day Tom says to his mother，“When I finish（完成）school，I want to be a dustman（垃圾工）．” “A dustman? ” his mother asks，and she is very surprised（吃惊的）．“Why do you want to become a dustman?” “Because then I only have to work．one day a week．”Tom answers．“Only one day a week?” his mother says，“What do you mean（意思）? And how do you know?” “Well”，Tom says，“I know that the dustmen who come to our house work on Thursday，because I only see them on that day．” 1．What is Tom like? A．Tom is a clever boy． B．Tom is lazy and he doesn’t like to work． C．Tom is a boy and he works very hard． D．Tom studies hard． 2．请找出一项与划线单词little意思一致的选项。 A．She eats little at lunch．She doesn’t want to be fat（胖）． B．What a nice little garden! C．Please give me a little of that cake． D．She knows a little Chinese． 3．What are Tom’s father and mother? A．His father is a doctor and his mother is a nurse． B．His father is a worker, and his mother is a doctor． C．His father is a doctor, his mother is a doctor too． D．His father is a worker, and his mother is a nurse． 4．What do Tom’s parents want him to be when he grows up（长大）? A．They want him to be a dustman． B．They want him to be an officer． C．They want him to be a doctor． D．They want him to be a teacher． 5．Why does Tom think that dustmen only work one day a week? A．Because Tom hears of（听说）this． B．Because a dustmen tells him． C．Because Tom sees the dustmen only on Thursday at his house． D．Because he doesn’t like doing any work．