Why didn’t you go to thegathering yesterday ——Itrained so hard and in addition, I ________ an important essay the wholemorning.

下列各句中，加点的成语使用恰当的一项是（ ）

I don’t know whether you happen ________ it, but I am going to study in the UK for a year.

The day _____ Nelson Mandela helped me was one of my happiest.

It was considerate _____ you not to play the piano while I was asleep