单词拼写。

1. You can _______  _______ (打电话给) Michael if you get to Fuzhou. He will meet you.

2. I think bad _______ (环境) can make people much stronger.

3. If you don't obey the traffic rules, you will _______  ________  ________ (受到罚款).

4. Thank you _______  _______ (邀请) my brother to your birthday party.

5. I'll call the restaurant and _______  _______  _______ (预订座位).

估算有限长线源产生的环境浓度时，必须考虑的是( )。

A．有限长线源的长度

B．有限长线源的源强

C．有限长线源两端引起的“边缘效应”

D．接收点的位置