催化装置在任何情况下都要确保再生、待生线路的料封的目的是防止（）。
A、催化剂跑损
B、再生温度低
C、反应温度低
D、油气互窜发生爆炸
参考答案：D
Would you please keep silent? The weather report and I want to listen. [ ]
A. is broadcast
B. is being broadcast
C. has been broad cast
D. had been broadcast
病毒性心肌炎发病初期的前驱症状不包括（）
A.发热
B.全身倦怠
C.恶心、呕吐
D.腹泻
E.腹痛
