电气线路的连接要求l区的电气线路宜采用( )接线盒。
A．本质安全型 B．正压型C．增安型 D．隔爆型
参考答案：D
I soon found that the work l was doing had already been done by somebody else， ,I was wasting my time. [ ]
A. in a word
B. with words
C. in other words
D. by word
新生儿坏死性小肠结肠炎的首发临床表现常为（）
A.腹胀
B.呕吐
C.腹泻
D.血便
E.喂养困难
