治疗急性牙髓炎时，首先应该考虑的问题是()
A．消炎
B．消灭致病菌
C．无痛或尽量减少疼痛
D．防止感染扩散
E．保护生活牙髓
参考答案：C
为什么矿井排水设备每年雨季来临前要进行一次联合试运转？
An inflatable liferaft should be manually released from its cradle by（）.
A.cutting the straps that enclose the container
B.removing the rubber sealing strip from the container
C.loosening the turnbuckle on the securing strap
D.pushing the button on the hydrostatic release
