We should eat more vegetables and fruit to keep___________/helθI/.

Could you do me a favor?—It depends on _______ it is.

Of the two best-sellers，which do you think is________tome

My cat’s really fat.— You_______have given her too much food. [ ]

It’s smoggy these days. That’s terrible!—Yes, I hope to plant trees. ______ trees, ______air pollution.