He enjoyed great success in the business, but his health _____as a result of years of hard work.
The engineers must have worked out the design by the end of last week,_______?
It rained a lot during their journey,so they _______ have had a good time.
—Isn’t that Ann’s husband over there?—No, it _______ be him—I’m sure he doesn’t wear glasses.
We hope that as many as possible _______ join us for the picnic tomorrow.
—I seldom watch TV, but listen to the radio a lot.—_______.