In his speech, Marks made the point ______ far more people died from smoking than from taking drugs.

Nancy reminded me of what I should ________ have forgotten.

-- Could you help me find some information on the net?--I’m occupied now. _______, I’ll do it later.

The driver has much experience of driving, and _____ he behaved very calmly in the dangerous situation.

—You don’t see the professor from Singapore quite often, do you? —No, we only meet ______．