有一位同学在学习凸透镜成像规律后，对光学产生了浓厚的兴趣，特意买了一块放大镜带回家探究，老师提示：千万不要拿放大镜对着太阳看，请画图并分析，这种做法可能产生什么危害？

22. We know a good deal about the people who lived in China 4, 000 years ago, because they ______write and leave written records for those who lived after them.

A．could

B．should

C．must

D．Shall