压缩机的排气温度不应超过150℃，做出这样的规定是基于（）。
A.排气压力
B.吸气温度
C.油的闪点
D.排气温度
参考答案：C
—Is Jack in the classroom now?
—No, he football on the playground.[ ]
A. plays
B. played
C. is playing
D. was playing
对炭疽的治疗首选药物（）
A.四环素
B.红霉素
C.喹诺酮类
D.青霉素
E.氯霉素
