—Could we go and visit the Summer Palace?

—Yes，________.This should be on our list of things to do in Beijing.

A．a pleasure

B．it depends

C．don't mention it　

D．by all means

交感性眼炎（）

A．隐蔽抗原

B．修饰抗原

C．抗独特型抗体

D．抗同种异型抗体

E．交叉反应性抗体