Ⅰ.单项选择（15小题，每题1分，共15分）
1．﹣﹣﹣What have you decided to be？
﹣﹣﹣A scientist．（ ）
A．thought of B．made up your mind
C．gone on
2．The world's population is increasing fast．（ ）
A．showing B．giving C．growing
3．Why should we protect animals？
If not，they will die out．（ ）
