In fact fuels we burn and plant food we eat ________ their chemical energy in the form of heat.

What do you think of the house—It is much more beautiful than________．

14．The nunther of the students who took part in the competition____500，but only a small number ofthem chosen。

Don’t me. I can hear you very well.

Do you like to go on the holiday in Hainan with me— I’d love to, but I cannot ___ the time.