一、单句语法填空。
阅读下面每句话，在空白处填入适当的内容（1个单词）或括号内单词的适当形式。
1. Unfortunately, Jerry cannot be with us today so I am pleased to accept this award on behalf ________ him.
2. Nowadays, many experts have ________（advocate） rewarding the children for their good behavior.
3. There are many people who have a ________（commit）like yours, but they don’t believe they have the power to do anything to improve our environment.
