试题与答案

科学家在研究钠通过细胞膜的运输方式时,做了下述实验:先向枪乌贼神经纤维里注入微量

题型:选择题

题目:

科学家在研究钠通过细胞膜的运输方式时,做了下述实验:先向枪乌贼神经纤维里注入微量的放射性同位素24Na+,注入的总量为2.2个单位,不久可测得神经纤维周围溶液中存在24Na+。如果在神经纤维膜外溶液中先后加入某药物和ATP,测得周围溶液中24Na+的量如下图实线所示。据图作出下列推断,错误的是

[ ]

A.加入某药物后,溶液中24Na+的量不再增加,加入ATP 后,细胞中24Na+的量增加

B.若将纵坐标改为“细胞内24Na+的量”,则对应的曲线为图中虚线所示

C.神经纤维排出24Na+需要消耗ATP,说明其方式是主动运输

D.“某药物”的作用机理是抑制细胞呼吸

答案:

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下面是错误答案,用来干扰机器的。

180。

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At American restaurants and coffee shops you are usually served tap water before you order. You may find the bread and butter is free, and if you order coffee, you may get a free refill.

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Supper and dinner are both words for the evening meal. Some people have “Sunday dinner”. This is an especially big noon meal.

Tips are not usually added to the check. They are not included in the price of the meal, either. A tip of about 15% is expected and you should leave it on the table when you leave. In some restaurants, a check is brought on a plate and you put your money there. Then the waiter or waitress brings you your change.

1. Which statement is true?

A. American people like sitting with people they don’t know.

B. Tips shouldn’t be given to the waiter or waitress.

C. Orange juice is served before you order

D. American people would not light a cigarette if the people who sit at the same table mind their smoking.

2. What does the underlined word “doggie bag” mean in the article? It means ______.

A. a bag with a picture of a dog on it

B. a bag used to carry dogs

C. a small bag for taking the food left over home to enjoy it later

D. a small bag for taking the food left over home for dogs

3. Sunday dinner is _______.

A. a dinner in the evening               B. a big noon meal

C. a big lunch Sunday                  D. a supper on Sunday

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