同步电复律是
参考答案:以R波为同步
管型检查时至少应观察多少个低倍视野
A.5个
B.10个
C.15个
D.20个
E.25个
I ______your address, otherwise I______you long before.
A.had forgotten,had visited
B.forgot, have visited
C.forgot,would have visited
D.have forgotten,would visit