对卡介苗的解释，你认为哪种是正确的（）
A.无毒牛型结核杆菌死菌，能减少感染后的发病和减轻病情严重性
B.无毒牛型结核杆菌活菌，能减少感染后的发病和减轻病情严重性
C.无毒人型结核杆菌活菌，能预防结核杆菌感染
D.无毒牛型结核杆菌活菌，能预防结核杆菌感染
E.减毒牛型结核杆菌死菌，能预防结核杆菌感染
参考答案：B
解析：卡介苗（BCG）是活的无毒力牛型结核菌疫苗。接种卡介苗可使人体产生对结核菌的获得性免疫力，提高其对结核病的抗病能力，并不能预防感染，但能减轻感染后的发病和病情。
| 短文改错。 该行多一个词：把多余的词用斜线（／）划掉，在该行右边横线上写出并划掉。 该行缺一个词：在缺词处加一个漏字符号（∧），在该行右边横线上写出该加的词。 该行错一个词：在错词下画一横线，在该行右边横线上写出该改的词。 该行若无错误：在该行右边横线上画一个勾。 | |
| Stephen, It’s very king for you to write me and let me know about your beautiful city. Now I’d like tell you something about my hometown The city stood on the bank of a long river. It is a beautiful place for people to live in. Its economy has been developing rapid in the last ten years. New factories, houses and roads have built. More schools and hospital are available for people here. Therefore, there is still some problems, such as water, air pollution and heavy traffic in rush hours. In my opinion, the city should develop their economy scientifically. I also think that a growth of its population should be under the control so that we’ll have a better hometown in the near future. Yours, Lihua | 1. _____ 2. _____ 3. _____ 4. _____ 5. _____ 6. _____ 7. _____ 8. _____ 9. _____ 10. _____ |