—On my part, we'd better invite some of our school friends from other grades to our party.
--- Shall we go out for a walk? --- Sorry. This is not the right _____ to invite me. I am not in the mood to walk now.
Please remain ______; the winner of the prize will be announced soon.
In our school students are _______ according to how much they know and how old they are.
I was_______ about it. I thought you were responsible and that’s why I scolded you. Please forgive me.
Every possible means ______to prevent the air pollution, but the sky is still not clear.