The answer is connected with the main use ______ the body makes of food— to supply the energy for movement.

h songs are fun But ________ that, they’llhelp you improve your English skills

_____ does she chat with friends on the Internet— Once a week.

When you stand on the top of the mountain and overlook the surrounding scenery，you’ll find it is________to climb it up with effort.

That black T-shirt which has Messi’s picture on it______be David. He admires him a lot.— It _____ be his. He prefers black to other colours.