问题 单项选择题

产生抗体的细胞是()

A.吞噬细胞

B.靶细胞

C.T细胞

D.浆细胞

答案

参考答案:D

解析:抗体由浆细胞合成并分泌,化学本质是免疫球蛋白,属于分泌蛋白,其合成与核糖体、内质网、高尔基体和线粒体有关,主要存在于血清中,少数存在于组织液和外分泌液中,抗体与抗原特异性结合,抑制病原体的繁殖和对人体细胞的黏附。在多数情况下,抗原、抗体结合后会发生进一步的变化,如形成沉淀或细胞集团,进而被吞噬细胞吞噬消化。考点:考查抗体的知识。点评:难度较小,熟记产生抗体的细胞。

阅读理解

Bowing is a very important custom in Japan. Unlike people in many other countries, they greet each other by bowing instead of shaking hands. It is impolite not to return a bow to whoever bows to you.

Bowing has many functions in one. It expresses the feeling of respect, thanks, regret, and so on. You can bow when you say, “thank you”, “sorry”, “hello”, “goodbye”, “congratulations”, “excuse me”, “good morning”, and more.

Bowing seems simple, but there are different ways of bowing. Bowing techniques vary from a small nod of the head to a long, 90-degree bow. It depends on the social position or age of the person you bow to. If your opposite is of higher social position or older than yourself, you are supposed to bow deeper and longer than him or her. It is polite to bow from your waist. Men usually keep their hands at their sides, and women usually put their hands together on their legs with their fingers touching. If it is not a very formal situation, you can bow by nodding. The most common bow is a bow of about 15 degrees.

You might feel strange doing it, but try to bow in Japan. You will be considered very polite!

小题1:The author writes the passage mainly to _____.

A.introduce the history of bowing in Japan

B.describe the purposes of bowing in Japan

C.describe different ways of bowing in Japan

D.introduce the Japanese custom of bowing小题2:By saying “Bowing has many functions in one”, the author means that _____.

A.one kind of bow has many similar functions

B.people can express different feelings by bowing

C.people bow to express their feelings

D.the more times you bow, the more respect you receive小题3:How people greet in many countries?

A.by bowing

B.by shaking hands

C.by kissing each other

D.by touching小题4:If an assistant wants to show respect to her professor, she may bow like _____.

A            B          C           D

单项选择题