对于小学生来说，每天写作业是很正常的。

It's completely ___normal for elementary students to do homework every day.

体检报告显示他的各项指标都很正常。

The medical checkup showed all his results were ___normal.

这条线必须与墙面垂直。

The line must be ___normal to the wall surface.

这种植物的最佳生长条件是在正常温度和湿度下。

This plant grows best under ___normal temperature and humidity conditions.