关于髋关节结核，下列错误的是

A．单纯骨结核多见

B．脓液可进入盆腔

C．儿童多见

D．不易早期发现

E．一般为单发

—______ nice day it is today! Let's go out to play, shall we?

—That's a good idea. [ ]

A. How a

B. What a

C. How