Questions 19 to 21 are based on the passage you have just heard.
A. The function of the human immune system.
B. The cause of various auto-immune diseases.
C. The viruses that may infect the human immune system.
D. The change in people’s immune system as they get older.
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Questions 19 to 21 are based on the passage you have just heard.
A. Report their illnesses.
B. Offer blood samples.
C. Act as research assistants.
D. Help to interview patients.
Questions 22 to 25 are based on the passage you have just heard.
A. His students had trouble getting on with each other.
B. A lot of kids stayed at school to do their homework.
C. His students were struggling to follow his lessons.
D. A group of kids were playing chess after school.
如果组件没有使用标签,该组件在渲染的时候，组件起始标签和结束标签之间的任何内容都会被抛弃，并不会起作用。
A. 对
B. 错
Vue提出了插槽（Slots）的概念，插槽就是定义在组件内部的template模板
A. 对
B. 错
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