问题 选择题

在制作口腔上皮细胞时,为了更清楚地观察细胞的结构,可以对细胞进行染色,用的染料是(  )

A.蒸馏水

B.清水

C.碘液

D.生理盐水

答案

制作人体口腔上皮细胞临时装片的正确步骤简记为:滴→刮→涂→盖→染.

滴是指在洁净的载玻片上滴一滴生理盐水.

刮是指用消毒牙签在漱净的口腔侧壁上轻轻刮几下.

涂是指把牙签附有碎屑的一端在载玻片的生理盐水滴中均匀涂抹.

盖是指盖上盖玻片,先用镊子夹起盖玻片的一边,让另一边先接触载玻片上的生理盐水滴.

然后轻轻盖上,避免出现气泡.

染是指染色,把稀碘液滴在盖玻片的一侧.

用吸水纸从另一侧吸引,直到染液浸润到标本的全部.

故选:C.

阅读理解

阅读理解。

     I am a student in Grade One in a middle school in Beijing. My name is Hong Kong. Susan is my pen pal. She is

twelve. She is in Grade Seven in a middle school in the USA.   My English teacher says we are in the same grade.

How funny it is!

     In her letters, Susan says she goes to school five days a week.   She gets to school at 8:30 in the morning. She

doesn't go home for lunch but has it at school.   She comes back home at three in the afternoon.   Sometimes she

plays games with her friends after school. She often has little homework. She likes movies too. Do you know who

is her favorite movie star? It is Jackie Chan. New Police Story is her favorite movie. It's an action movie.

1. Susan is a _________

A. Chinese girl              

B. school girl                

C. boy                  

D. teacher.

2. What is the word " pal"? It means ______

A. student            

B. friend            

C. teacher          

D. letter

3. Susan ____ early in the afternoon.

A. goes to school       

B. goes home          

C. has classes      

D. has lunch

4. What does the underlined word " it" mean?

A. We are in the same grade                    

B. I'm in Grade One

C. Susan is in Grade Seven.                    

D. Both A, B and C

5. Which following sentence is right?

A. I'm a student in Grade One in a middle school in Tianjin.

B. Susan doesn't do any homework

C. Susan has lunch at school.

D. Susan often goes to a shop near her house after school.

多项选择题