______ do you write to your parents? 　　 — Once a month. [ ]

I need something for cutting the paper.－ Oh, you want a knife? OK, I’ll get ______ for you.

It is _________ difficult work that we can’t finish it in a short time.

When he got ____,he took elephants,camels, lions and monkeys to his wedding.

The little boy ________ his seat to an old lady on the crowded bus.