强心甙中毒引起的窦性心动过缓的治疗可选用（）
A.氯化钾
B.阿托品
C.利多卡因
D.肾上腺素
E.吗啡
参考答案：B
—"Why are you so happy today?"
—"Because I was chosen _______ of the charity show." [ ]
A. be the host
B. to be the host
C. being the host
D. was the host
皮带输送机断带主要原因有（）
A.负荷太大
B.断卡、磨损过限
C.滚筒不转
D.有水
