一般规定,在两种燃气互换时华白指数的允许变化不大于()。
A、±5%~±10%
B、±5%~±15%
C、±10%~±15%
D、±10%~±20%
参考答案:A
He is very popular among his students as he always tries to make them_________ in his lessons. [ ]
A. interested
B.interesting
C. interest
D.to interest
不属于阵发性室上性心动过速临床特点的是()
A.突发突止
B.心率>150次/分
C.心律绝对规则
D.第一心音强弱不等
E.大部分由折返机制引起