He has been out of work for three months; as a result, he has to ____on family expenses by one-third.

I think humour is a vital form of entertainment, ____ it makes us laugh and laughing keeps us healthy

We should ________ our help as soon as our friends ________.[ ]

The postman comes at 6:30 in the morning, ____ time I am usually fast asleep.

With some snow on top of it,the Yellow Mountain looked fantastic this winter.Actually, I doubt whether we could visit ______mountian in China.