问题补充:
— I borrow your English book?
—Yes, of course you .
A. Could; could
B. Must; can
C. Could; can
D. Can; could
答案:
A. Could; could
B. Must; can
C. Could; can
D. Can; could
解析:can,could表示许可,可以做某事,could比can更委婉一些must的含义是必须,对于must开头的疑问句,否定回答通常用needn 或not have to ,表示不必.以could和can开头的句子,常用can 或can’t来回答。故选C。