It is usually warm in my hometown in April, but it ________ be rather cold sometimes.

--______you swim? -- No, I can’t. 

--Why are your eyes so red? You _______ have slept well last night.---Yeah, I stayed up late writing a report.

You can not imagine that a well-behaved gentleman _______be so rude to a lady.

— Congratulations! You’ve got the first prize in the English Contest.—_____ it be true? It’s unbelievable!