-Can you __________ to my house to have a party tonight?

-__________, but I have to visit my teacher.[ ]

A. come over; Sorry

B. come on; Sure

C. come over; Sure

D. come on; Sorry

经验鉴别习称的“挂甲”是指（）

A.阿胶的性状

B.熊胆的性状

C.牛黄的性状

D.五味子的性状