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问题 选择题

下列叙述中不属于细菌特点的是:

A．有细胞壁、细胞膜和细胞质等结构

B．为单细胞生物

C．有些细菌具有荚膜

D．细菌细胞内没有遗传物质

答案

答案：D

细菌细胞的基本结构为：细胞壁、细胞膜、细胞质、遗传物质等．

A、细菌有细胞壁、细胞膜和细胞质等结构，故A说法正确；

B、所有的细菌都为单细胞生物，故B说法正确；

C、细胞核包括内部的遗传物质和外面的蛋白质外壳，细菌有遗传物质但无核膜，故细胞核未成形，故C说法正确；

D、细菌细胞内有遗传物质，故D说法错误符合题意；

故选：D

单项选择题

吸虫生活史中幼虫在淡水螺内的增殖为

A．进行孢子生殖

B．进行配子生殖

C．进行幼体增殖

D．不繁殖

E．进行接合生殖
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单项选择题

It was a very hot day in the middle of summer, and there were no trees along the street. Mr. Read (41) his shop at half past five, and went out into the street and began walking to the bus. He was a very (42) man. The sun shone straight down the street, and in a few minutes Mr. Read (43) very hot.

A. opened B. reached C. closed

A small boy came out of another (44) in the street and followed Mr. Read. He stayed very (45) him all the time, and he kicked Mr. Read’s (46) several times. Mr. Read looked at him angrily each time.After the fourth time, Mr. Read stopped, turned (47) and said to the small boy, "What are you doing (48) following me like that! You’re going to hurt my feet."
"I’m (49) , but don’t stop me, please!" the small boy said. "It’s very hot today, and there isn’t (50) shade anywhere else in the street!\
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