问题 单项选择题

传染病在人群中发生流行的基本条件()

A.传染源、传播途径、易感者

B.必须有易感者的存在

C.必须有传染源的存在

D.在外界因素影响下,传染源、传播途径和易感者三个环节相互联系

E.病原体有机会侵犯机体

答案

参考答案:D

解析:此题属传染病流行病学的内容,考查传染病在人群中发生流行的基本条件。传染病在人群中发生流行必须依赖于三个基本条件,即传染源、传播途径和易感者。而且这三者必须在外界因素的影响下相互联系,缺乏任何一个环节,传染病都难以发生流行。故结合题意D为正确选项。

阅读理解

阅读理解

          Dinner customs (习惯) are different around the world. If you are a guest in Ghana(加纳), this

information will help you a lot.

          In Ghana, dinner is usually from four in the afternoon to six in the evening. But there are no

strict rules (规则) about time. Whenever a guest arrives. a family offers food. When you go to a

home, the person who receives guests takes you to the living room first. At this time everyone

welcomes you. Then you go to the dinning room. There you wash your hands in a bowl of water.

All the food is on the table.

         In Ghana you usually eat with your fingers. You eat from the same dish as everyone else.

But you eat from one side of the dish only. It is not polite to get food from the other side of the

dish. After dinner, you wash your hands again in a bowl of water.

         Most meals in Ghana have a dish called fufu. People in Ghana make fufu from the powder

(粉末) of some plants. Sometimes they cut the fufu with a saw(锯子) because it is very hard.

You must chew (咀嚼) fufu well, or you may get sick. You eat fufu with the fingers of your right

hand only.

1. From the passage we know that in Ghana _______ .

A. the rules for dinner time are not strict

B. dinner is always at six in the evening

C. a family offers food only at four in the afternoon

D. people usually invite their guests to dinner late in the evening

2. If you are a dinner guest in Ghana, the host (主人) always takes you to _________ .

A. the dining room first

B. the living room first

C. the kitchen first

D. the garden first

3. People in Ghana usually eat _______ .

A. from one side of a dish to the other

B. from the other side of the dish

C. with their fingers

D. with their spoons

4. In fact, most dishes in Ghana _______ .

A. are cooked with the powder of some plants

B. have fufu in them

C. are too hard to eat

D. are not very hard

5. When you eat fufu, you'd better ________ .

A. cut it with a saw

B. use your right hand only

C. chew it well

D. all of the above

选择题