--- Why did you buy two pairs of shoes? --- It was so hard to choose which was________, so I took them both.

Of the two T-shirts，I’d choose the___one to save some money for a book．

— Is Andy __________ than Amy?— No. Andy isn’t as__________  as Amy.

More and more people have a low-C life and the air is _________ than before.

The world’s population is growing ______ and there is _______ land and water for growing rice.