反映老年肾小球滤过功能的指标包括（）

A.血清肌酐

B.血清胱抑素C

C.尿β2-微球蛋白

D.内生肌酐清除率

E.Tc放射性核素肾动态显像

Jim has made many friends since he ______ to China.

A．came

B．comes

C．has come

D．will come