当你介绍朋友给别人认识,应该说________.A. I'm Mike.B. This is Li Lei.C. He's Li Ming.
—My mother has a backache in hospital —_________________.
—We’re going to Mountain Yandang this weekend. — _____.
— _____ Dasan is from Canada, he can speak Chinese very well. — I know he studies Chinese hard.
My sister is only two years old, and I have to _____ her on Sunday.
—What are you doing for your vacation? —________________________.