--Jim, put the things away and tidy（整理）your room.

-- Well, but I have ____ work to do, Dad.

A．many

B．a lot

C．lots of

D．too many

在泌尿系统疾病中，其不透光性结石占结石的（）

A.25%

B.40％

C.50%

D.70%

E.90％