问题 选择题

接种卡介苗可以有效预防结核病,其原因是(  )

A.卡介苗在人体内能激活人体的吞噬细胞,将结核杆菌吞噬了

B.接种卡介苗后能使人在不发病的情况下,产生抵抗结核杆菌的抗体

C.卡介苗能提高人体的各项生理活动,增强抵抗力

D.卡介苗进入人体后能直接消灭侵入人体内的结核杆菌

答案

疫苗是将病原微生物及其代谢产物,经过人工减毒、灭活或利用基因工程等方法制成的用于预防传染病的制剂;即疫苗是灭活的病原体,已不具有致病性,但能够刺激淋巴细胞产生抗体,即疫苗还具有抗原性,因此接种疫苗后能使人在不发病的情况下,产生抵抗某种病原体的抗体.

故选:B

阅读理解

阅读理解。

     Welcome to Franklin Hotel. To make you stay as enjoyable as possible, we hope you will use our facilities (设施) to the full.

     Dining Room: Breakfast is served in the dining room from 8:00 to 9:30 a. m. Also the room staff (服务员 ) may bring breakfast to your room at any time after 7:00 a. m. If this happens, please fill out a card and hang it

outside your door when you go to bed. Lunch is from 12:00 to 2:30 p. m. Dinner is from 7:30 to 9:00 p. m.

     Room Service: This operates 24 hours a day; phone the Reception desk, and your message will be passed

on to the room staff.

      Telephones: To make a phone call, dial (拨) 0 for Reception and ask to be connected. We apologize for

delays if the lines are very busy. There are also public telephones near the Reception desk. Tell Reception if

early calls are needed.

     Shop: The hotel shop is open for presents, gifts and goods from 9:00 a. m. to 5:30 p. m.

     Laundry: We have a laundry in the building, and we will wash, iron and return your clothes within 24 hours. Ask the room staff to collect them.

     Bar (酒吧):The hotel bar is open from 12:00 to 2:00 p. m. and 7:00 p. m. to 1:00 a. m.

     Banking: The Reception staff will cash cheques (兑现支票) and exchange any foreign money for you.

     You have come back to the hotel just to make an urgent (紧急) phone call. But you notice a lot of people

around the Reception desk. 

Judging from the notice, it would be quickest to ______ .

A. go to your room and phone from there

B. ask at the Reception desk

C. use one of the public telephones near the telephone desk

D. go out again and look for a public phone box

单项选择题