直接控制重大环境因素的途径有（）
A431环境因素
B443信息交流
C446运行控制
D447应急准备和响应
E451监测和测量
参考答案：C, D
Read and fill in the blanks. 补全对话。
A: Mum, I 1 feel very well.
B: What's the 2 ?
A: I don't know. I 3 a headache and a cough (咳嗽).
B: Let me take your temperature. It's a cold. Don't worry! You can 4 some medicine and 5 in bed for
a few hours. You'll feel better soon.
A: OK. I hope so.
1. 2. 3. 4. 5.
超声诊断有哪些局限性?
