美沙酮的化学结构为
A．双氯芬酸钠B．哌替啶C．美沙酮D．异丙肾上腺素E．右丙氧芬
参考答案：D
所给单词正确形式填空。
1. Jack wants ________ (make) friends in China.
2. I have a good friend _________ (call) Li Ming?
3. The Spring Festival _________ ( finish) at the Lantern Festival.
4. Life today is much _________ (easy) than that in the past.
5. Look! Some workers _________ (decorate) a building.
简述为确保加油机整体防爆性能符合要求，应怎样加强管理？
