If there aren’t so many cars, our air would be much ____.

dioxide, which makes a ______ between us andthe sun, prevents heat from getting out of the atmosphere easily, so the earthis becoming warmer

It’s kind ______them to give away money to UNICEF. It’s important _________ them to helppoor children go to school.

What’s your brother like —_____________.

er bought me _____ mp3, but I lost _____ mp3 yesterday