—Good morning. — [ ]
A. Hello.
B. Good morning.
C. How are you?
D. Nice to meet you?
答案:B
血液是流动的结缔组织.______.
正压式消防空气呼吸器操作前检查有哪些要求().
A.检查气密性
B.检查压力
C.检查腰带
D.检查重量