补全对话 从方框中所给的选项中选择正确的句子补全以下对话。(10分)
Students: Good morning, Miss Lin.
Miss Lin: 　 　　  Today, we'll talk about a new bird flu. It has hit some Chinese cities.
Monitor: 　 　
Miss Lin: Yes, it is. It's reported that about 35 people have been ill.
Monitor: 　 　
Miss Lin: We should keep away from animals. And we ought to wash our hands correctly.
Monitor: 　 　
Miss Lin: It should take at least 20 seconds each time. 　　　  See a doctor at once if you have a high fever or have trouble breathing.