He trained hard in puzzle-guessing, a sort of children’s game, all year, _____ still failed to reach his best form in all the tests given to both adults and children. 

Food safety is ________ important, so the government spares no efforts to prevent food pollution.

Mr.Smith used to smoke __________ but he has given it up.

— Are you going to travel during this summer vacation?— No, I’ll have to do some part-time job for my study. __________, there’s a disease spreading.

It is ______ to rain this afternoon.