根据句意及所给首字母写出句中所缺单词。

1. Don't b_____ late for class, boys and girls.

2. We can't listen to m_____ in class.

3. You have to wear your s_____ shoes for gym class.

4. There are 50 desks and chairs in our c_____.

5. What e_____do we have to do?

全身骨显像检查前的注意事项，下列哪一项是错误的()

A．静注显像剂后要大量喝水

B．静脉注射显像剂前需封闭甲状腺

C．检查时要憋尿

D．对于严重骨疼痛者适当使用镇痛剂

E．避免放射性尿液污染体表或衣服