—Why do you want to learn French?  

—I think it is fun _____ language after English.   [ ]

A. to learn a

B. learn a

C. to learn another

D. learning another

中厚皮片包含的组织成分有

A．表皮和真皮 * * 层
B．表皮和部分真皮
C．表皮和全层真皮
D．皮肤全层真皮
E．表皮