May Igo to the concert with you? — I’mafraid not ______ you have a ticket, because I have only one.

I don’t think teenagers should drive cars.— ____.They aren’t serious enough.

It was from the third floor of the teaching building ______ Tom shouted to me, “Wait till I set off.”

She sells second-hand articles at reasonably fair prices from 10 to 50 dollars ____ in her shop.

下列各句中，加点的成语使用恰当的一项是（ ）（3分）