There is no perfect person, some people have made _____success of themselves in spite of what would appear to be ______ weakness in their professions.

A．/, a

B．a, /

C．a, a

D．/, /

关于月经，下列哪项不正确（）

A.两次月经第一日的间隔时间为一个月经周期，一般为28～30日

B.月经提前或延后3日左右仍属正常范围

C.每次月经的出血量为经量，大约为100ml

D.月经血一般呈暗红色，主要特点是不凝固

E.由于卵巢功能尚不健全，故初潮后月经周期也多无一定规律