根据首字母提示在空白处填入适当的单词，使句子意思完整、语法正确
1. You should often r________ the old knowledge so that you can’t forget it.
2. It takes me more time to drive to work because of the heavy t________.
3. Bamboo is a common plant. It has many uses in our d________ lives.
4. When I was cooking for the first time, my mother stood b________ me and 
looked at me.
5. English is w________ used all over the world.