The research is so designed that, once _______, nothing can be done to change it.

I’d like a pen which ________well.—Will this one_______?

If the tickets to the match are not available, please give me a call _______.

Did you have a good trip yesterday—We got up late, and 　　　　the first train had left, 　　　　we had to take a taxi.

下列各句中，加线的成语使用恰当的一句是（ ）