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.
—What class are you in? —I’m ____.
—Who’s that, Kangkang? —____ Mary.
—____ is Mary? —She is five.
—Are they from Canada? —No, they ____.
—____, are you Mr. Wang? —Yes, I am.