— It’s raining. When did it start?— As far as I know, it ____ for three hours.
--How can young people realize their dreams? --No matter what difficulties they meet, they can’t ________.
Basketball ________ by a Canadian doctor ________ James Naismith.
People shouldn’t ________ take photos while seeing famous pictures in the art gallery.
We all think it’s dangerous for _________ to drive.
--Your classroom is so clean! -- ________. It is cleaned everyday.