有关肾错构瘤的描述，错误的是（）

A.错构瘤含有脂肪、平滑肌和血管成分

B.可偶见自发性出血

C.典型表现为双肾多发病变，偶见钙化

D.20%～40%的错构瘤患者伴发结节性硬化

E.可无临床症状

I was worried about my maths, but Mr. Brown gave me an A.（）

A.Don't worry about it.

B.Congratulations! That's a difficult course.

C.Mr. Brown is very good.

D.Good luck to you！