题目

用低倍镜观察菠菜叶的下表皮细胞时，发现视野中有一异物，移动装片异物不动，换上高倍镜后异物仍在，异物可能在（ ）A. 物镜上 B. 目镜上 C. 装片上 D. 材料中 答案：【答案】B【解析】显微镜中视野中污物可能存在的位置：物镜、目镜或装片。判断方法如下：先移动装片，污物动则在装片上；不动再转换目镜，污物动在目镜上，不动就在物镜上。故答案选择B。 When a cat is frightened, its heart starts beating faster, its muscles get tense, and there are changes in the chemicals in its blood stream. If the danger continues, it will defend itself, or it will run away as fast as possible. Something like this also happens to people. When we are excited, angry, scared or aroused by other emotions, our bodies go through many physical changes, all of which make us more alert and ready to react. We, too, get ready to defend ourselves or run．Human beings, however, have a problem that animals never face. If we give way to our feelings and let them take over, we can get into trouble. Have you ever said something in anger ― or hit somebody － and regretted it later? Have you ever shouted at a teacher, told somebody you were lonely, or said you were in love, and then wished later you had kept your mouth shut? It isn’t always wise to express your feelings freely. Does this mean that it’s smarter always to hide our feelings? No! If you keep the feelings of anger, sadness, and bitterness hidden away or bottled up inside, your body stays tense. Physical illnesses can develop, and you can feel disturbed badly inside．It can actual1y be bad for your health. Feelings that you keep all bottled up inside don’t just go away. It’s as if you bought some bananas and stuck them in a cupboard. You might not be able to see them, but before long you’d smell them. And if you opened the cupboard, chances are that you’d see little fruit flies hovering all over them. They’d be rotten. You can try to treat emotions as if they were bananas in the cupboard. You can hide them and you can pretend they don’t exist, but they’ll still be around. And at last you’ll have to deal with them, just like those bananas. 72. By taking a cat as an example, the author wants to show us that         . A. animals can’t control their feelings B. people can’t control their feelings C. people’s physical reactions are like those of animals in a way D. our bodies go through many physical changes in certain situations 73. It’s mentioned in the passage that human beings get into trouble because        . A. we are not as alert as animals B. we sometimes can’t control our feelings C. we always do something wrong to other people[来源:ZXXK] D. we don’t pay attention to our physical changes 74. The author wants to tell us in the last two paragraphs that        . A. we won’t be able to completely get away from our feelings . B. we should treat emotions like bananas in a cupboard C. feelings will gradually disappear when we hold them in D. it’s good for our health to keep pleasant feelings 75. What would be the best title for the passage? A. Frightened Cats and Human Beings         B. Feelings and Bananas C. Deal with Feelings Wisely                 D. Express Feelings Freely