The dam is 3800 ___. It is a 980 ___ dam at the base.

At the meeting they discussed different ______ to the study of mathematics.

This book gives a brief ________ of MoYan’s growth and details of his writing experiences.

Mr. Chen drove all the ___ to Wuhan to attend the meeting.

 ---What did our teacher do?---He raised his arm as a(n)        for us to stop.