It was a serious mistake, ______ caused by carelessness.

They might just have a place ______on the writing course一why don’t you give it a try?

What do you think of the lion? －Well, I think it’s _____ ugly animal.

My grandma started using Weibo at the age of 70. She always says it’s never ____ old to start doing things.

Do you like swimming in winter? —Of course.The water________a bit cold at first but then I am warm and full of energy.