Babies often ______ down when they are learning to walk.

单项选择题He is very ______ in using money.

单项选择题She ______ the washing out in the garden because it was fine yesterday.

单项选择题Our society has changed and ______ in it.

单项选择题Do what you think is right, ______ they say.

单项选择题Living things are ______ cells, and cells do not grow to more than twice the size they were at first.