(2013·成都七中考前模拟)If you decided to study in America, you have no choice but ________ your English greatly.

While crossing the street, an old man was knocked down by a car and badly __________.

I regret to say your performance didn’t reach the relevant requirements, ______you cannot be accepted by the company.

I was about to walk over to Tom’ s seat when he ________ and left.

_________ the lecturer more clearly, I arrived early and chose a front seat.