It should be emphasized that our technology has great potentials ________ food development in China.

Colours can make us _______ or sad.

The problem is ________ sometimes when we are given something on a constant basis, we start to take them for granted and forget being thankful for what we already have

I don’t like those big cities which havegot ____ people and ____ traffic.

Remember to______ a stamp on the envelope before you post it.