根据句意，用所给词的适当形式完成句子：

1．The river _________ （pollute）badly．There are no living things in it．

2．Boys and girls，you must pay attention to the traffic _________（safe）．

3．Edison had many _________（invent）in this life．

4．We study hard in order to get a higher _________（educate）．

5．The teacher enlarged the picture on the screen to make it _________（see）clearly by all the students．