根据句意，用括号中所给单词的正确形式填空，并将答案填写在答题卡对应的横线上。

【1】Each of the students is_________(ask) to take a dictionary to the English class.

【2】It is very important to know how to ask for help_________(polite).

【3】The teacher decided to go to the meeting as an_________(express)of support.

【4】Our teacher always warns us not_________(swim)in the river.

【5】Mr.Smith gave us a_________(suggest) about how to improve our speaking skills.