问题 单项选择题

病原携带者的特点是

A.病原体完全被清除
B.病原体潜藏在组织中
C.病原体引起免疫反应,并发生明显的组织损伤
D.病原体经常排出体外
E.病原体未引起组织损伤但引起免疫反应

答案

参考答案:D

解析:按发生于显性或隐性感染期之后分为恢复期携带者与健康携带者。发生显性感染临床症状出现之前者称为潜伏期携带者。按恢复期携带病原体持续时间在3个月以内或以上又分为急性与慢性携带者。所有病原携带者都有一个共同的特点,即不显出临床症状而能排出病原体,是重要的传染源。

阅读理解

阅读理解。

     If you open today's newspaper, what do you see? Ads! Look through a magazine. More ads! Turn on

the TV. Still more ads! Everywhere you look, someone has something to sell.

     Here are some ways ads get us to buy. Some ads use famous people. Stars are paid to sell a product.

Think about it. Do they really know about medicine? Do they know about soft drinks? There people may be

famous, but they may not know about what they are selling.

     Some ads make you think you're getting the word of an expert. They say, "Doctor said." A man in a white

coat comes on TV. He looks nice."I use Bright and White," he says. This man looks like a doctor. But he is

an actor. He has been paid to sell this product.

     Does soap have anything to do with a pretty child? But ads may show their product with something nice,

such as the sun, the flowers and so on. Such an ad is about feelings rather than facts. Ads are full of strong

words. Words like "new" and "improved" have strong influence. They can help a product sell. The soap may

be called "Spring Rain". A car may be called "Tiger". Strong words work on our feelings. Some ads make

promises (承诺). But can they keep them? No.

     Some ads use our fear of being too late. "Buy now!" they say. "Selling ends soon." Check to see if this is

true. Don't hurry. Take time to think. All ads hope we will buy something, do something, or think in a certain

way. Know what ads are doing. Ask questions to yourself. Don't let their words and pictures fool you.

1. Why do famous people appear in ads?

A. Because they know every product well.

B. Because they want to serve the people.

C. Because they can make money from the ads.

2. The underlined word "expert" in Paragraph Three probably means _______.

A. 主持人

B. 专家

C. 演员

3. According to the passage, which of the following is NOT true?

A. The famous people may not know about what they are selling.

B. Some ads make promises to people and they can keep them.

C. Ads are full of strong words, such as "new" and "improved".

4. According to the passage, we know that "Tiger" might be the name of  _______.

A. a kind of car

B. a kind of computer

C. a kind of soap

5. What does the writer want to tell us?

A. We should not always believe the ads.

B. We should buy things that ads ask us to buy.

C. We should think about ads before buying things.

名词解释