将下列句子中汉语部分译成英语，注意使用适当的形式，并将所填单词写在相应位置。

1. If you learn to _______ difficulties, you will be the winner in life. (克服)                       

2. I often have a glass of  _______  and an egg for breakfast. (甜牛奶)                               

3. People are not allowed to  _______  in a museum.(拍照)                                             

4. _______ is becoming more and more serious in today's world. (水污染)                               

5. As students, we should study hard, _______ it's important for us to get on well with others. (同时)

简述我国中小学常用的德育原则。