问题 选择题

小明同学在用显微镜观察人的口腔上皮细胞装片时,发现视野内有一污点,转动目镜和移动装片时,污点均不动,你认为污点最可能位于下列哪一结构上

A.反光镜

B.目镜

C.物镜

D.装片

答案

答案:C

题目分析:显微镜视野中如果出现污点只有可能出现在目镜、物镜或玻片上,不会出现在反光镜上,因为反光镜上的污点只会多少影响视野的明亮程度,不会出现在视野中,在观察植物细胞时,视野中出现了一个污点,先移动载玻片再转动目镜,污点都没有移动,说明污点不在载玻片和目镜上,那么污点就一定在物镜上,所以在观察植物细胞时,视野中出现了一个污点,先移动载玻片再转动目镜,污点都没有移动,则说明污点在物镜上,故选C。

完形填空

Eric was standing in front of a large, gray house in the countryside. His mother told him that  he was going to spend the next twelve days there with no TV, no mobile phone and worst ofall-no _    .

Just then,a       came into the house. When he saw EriC, he went up to him. "I'm     you are Eric. Welcome to Camp Reboot," said the man. "I'm Tony, the camp leader, but you will _   me  'Sir'. Now you tell me why you're here."

Eric quickly replied, "My mum made _   come here!" When Tony looked angrily at him and did not say anything, Eric realized his mistake and added, "Sir!"

“And do you know     your mother sent you here?" asked Tony.

“She thinks I spend too much time online-that I can't _   without the Internet. Sir," answered Eric.

“It's not just her opinion. It's the truth! Look at you—      ,unhealthy and certainly not getting enough sleep. At Camp Reboot, you're going hiking, boating, rock-climbing and stay outdoors most of the time," said Tony.

Eric's heart broke.

    it's not going to be all fun and games." Tony continued. "We have rules here. If you break them, you'll _   be sent home! Instead, you'll have to sweep the floor, wash the dishes or do an extra hour of exercise!"

“Oh, my God!" cried Eric. "What have you got me into, Mum?"

小题1:

A.clock

B.camera

C.book

D.computer小题2:

A.man

B.woman

C.dog

D.cat小题3:

A.sad

B.sure

C.busy

D.surprised小题4:

A.give

B.make

C.wish

D.call小题5:

A.me

B.you

C.him

D.her小题6:

A.what

B.who

C.when

D.why小题7:

A.run

B.walk

C.live

D.sing小题8:

A.happy

B.tired

C.smart

D.clean小题9:

A.But

B.So

C.Or

D.Though小题10:

A.often

B.also

C.never

D.still

单项选择题