甲×23=乙×34,
所以,甲:乙=23:34=8:9,
故答案为8:9.
房性早搏的心电图特点是()。
A.QRS>0.12s
B.P′-R>0.12s
C.P’波提前出现
D.代偿间期不完全
E.提前出现的QRs波群无提前出现的P’波
My mother often _____ me ____ housework on Sunday.
A. make… do B. makes …does C. makes …do