Earth Day is celebration of life and our planet. It is a reminder that we need to ________the world we live in and that we should learn to respect life and nature.
—Do you mind ________alone at home? -No,but I want a good book________.
Science and technology is changing fast nowadays. I bought this MP3 player at the beginning of this year but now it's out of________.
They didn't allow ________the camp without a special pass.
If you leave,I'll have ________friends here,so I won't stay________.
Jack ________the bus as soon as it stopped,then to his joy he met his best friend at the station.