题目

下列有关物质进出细胞方式的叙述，正确的是（） A . 人的肝细胞吸收氨基酸和葡萄糖都需要载体 B . 酵母菌产生的蛋白质分子通过载体的作用排到细胞外，并且要消耗能量 C . 植物根毛细胞吸收K+的速率与土壤溶液中K+浓度成正比 D . 小分子或离子都可以通过自由扩散进入细胞内 答案：A    If we want to get on well with boys and girls properly, here are some "dos and don'ts" for you to follow     Keep a normal and healthy state of mind. Our schools and classes are made up of boys and girls," It is very natural for the boys and girls to make friends with each other. We should make as many friends as possible. We should not keep in touch with the other sex (性别)in secret.     Don't be too nervous or too shy. If you are a shy person, you can also find a way to make friends. First of all, you can make friends with the students who have the same interest and hobby as you. As both of you have much in common, you may have much to talk about. If you keep doing things like that, little by little, you will find you are as free to express yourself as others.     Don't fall into the ditch of early love. Boys and girls at adolescence  (青春期)are rich in feelings. They easily regard friendship as love and fall in love with each other at an early age. In my opinion, early love is a green apple that can't be eaten. An apple won't taste sweet until it is fully ripe. Boys and girls at middle School are too young to carry the heavy burden of love. Keep out of early love. (   )51. The main idea of the passage is to______. A. tell students to keep away from early love B. advice boys and girls how to get on well with each other C. tell students how to make friends with adults (   )52. We should keep in touch with the other sex in the following ways EXCEPT______. A. with a good state of mind B. in real friendship C. in secret (   )53. If you are a shy person, you can_______. A. find friends with the same interest and hobby as you B. only have a few friends of the same sex C. not make friends with the other sex (   )54. What does the underline word "ditch" mean? A. 波浪 B. 泥潭 C. 圈套 (   )55. A person at young age_______. A. easily regards friendship as love     B. is good at making friends with each other C. is old enough to fall in love