问题 单项选择题

环状沉淀试验中要求()

A.抗原澄清

B.抗体澄清

C.抗原和抗体都必须澄清

D.对抗原和抗体没有特别要求

E.抗原比重大于抗血清

答案

参考答案:C

解析:环状沉淀试验:在一定内径(1.5~2.0mm)的玻璃管中先加入抗血清,再沿管壁加入抗原溶液,因抗血清比重大于抗原,故在两者交界处形成清晰界面,此处抗原抗体生成物在一定时间内形成白色环为阳性。要求:抗原抗体溶液澄清。适用于微量抗原测定。考点:环状沉淀试验

阅读理解

Have you felt annoyed when a cell phone (手机)rings during the class? Something must be done to stop this. Now in New York City, USA, a rule is carried out(执行) in schools. Students can’t even bring cell phones to school. Is it a good thing or not?

Anxious(焦虑的) parents say that cell phones are an important tool in holding New York City’s families together.

“I worry about it,” said Elizabeth Lorris Ritter, a mother of a middle school kid. “It’s necessary in our everyday life. We have a washing machine, we have running water, and we have cell phones.”

A number of Americans think cell phones connect them to children on buses, getting out from subways, walking through unknown places.

“I have her call me when she gets out school,” said Lindsay Walt, a schoolgirl’s mother. “No one in New York is going to let their children go to school without a cell phone.

What about the cell phone owners, the students? Most of the students said that cell phones were necessary and the cell phone was like an extra(额外的)hand or foot for them.

“I feel so empty,” said May Chom, 14. “There is also no way to listen to music on the way to school without my phone. It will be a really, really boring trip.”

小题1:. Elizabeth Lorris Ritter is worried that ______________.

A.students are not allowed to bring cellphones

B.students spend too much time in listening to music on the cellphones

C.students bring cellphones to school and they often ring during the class

D.no rule is carried out to stop students from bringing cellphones to school小题2:. ____________ American parents disagree with the rule that students can’t bring cellphones to school.

A.Many

B.Some

C.Few

D.No小题3: May Chom likes to ______________.

A.go to school without a cellphone

B.chat with her friends on the cellphone on the way to school

C.walk through unknown places with a cellphone

D.bring a cellphone to school小题4: This writer wants to tell us the __________ in carrying out the rule not

to use a cellphone in school.

A.importance

B.problem

C.happiness

D.impossibility (不可能)

填空题