Li Lei knows two foreign languages. He can speak _______ English______ French.

— Professor Smith, some students want to have a talk with you. ___ they wait here or outside?— Show them in now, please.

The problem is too difficult for him. He _______ solve it by himself without any help.

Susan’s parents bought a large house with a swimming pool. It ______be very expensive.

—Isn’t Ann’s husband over there? —No, it _____ be him — I’m sure he doesn’t wear glasses.