I’ve always DengXiaoping for his courage’ and degeneration to push China forward

Only after they had carried out over ten experiments ______ the decision.

下面选项中语言表达得体的一项是

There was a lot of fun at yesterday’s party. You ________ come. Why didn’t you?— What a pity! But I had no time because I had lots of homework to do.[ ]

I expect all my letters ____ promptly. [ ]