Dinner is ready．Help yourself!—Wow! Thisdelicious．Could you please tell me how to cook it?

It’s cold .you’d betteroff your coat .

The man in a black suit _______ be our youth worker.— I’m sure it _______ be him. I saw him in the laboratory building some minutes ago.

Tom，________his brother，________playing computer games.

My mother often tells me not to ________ or not to look down upon others.