My CD doesn't work well. I'll go and _______ this evening．

A．have them repaired

B．to repair

C．have it repaired

D．have it repair

WHO建议，按照65岁以上老年人口系数达到多少百位比为老年型社会（）

A.5％

B.6％

C.7％

D.8％

E.9％