The elephant is _____________ the dog. [ ]
A. as light as
B. as small as
C. bigger than
答案:C
找规律填数。
64,32,16,( ),( ),( )。
Ⅰ度房室传导阻滞的心电图特点,主要是()
A.P波增宽
B.出现f波
C.P-R间期延长
D.P-R间期逐渐延长,直至一个P波后漏脱一个QRS波群
E.P波与QRS波毫无相关性