根据汉语提示填空。
1.我们应该让孩子们远离河边。We should _______ the children _______ from the river.
2.Our teacher is _______(参加，出席）a meeting at the moment.
3.It’s _________(必要的）for us to master a foreign language.
4. In my opinion,it’s not a good idea to _______(惩罚）kids every time they make mistakes.