牙医建议使用扩弓器来调整我的牙齿排列。

The dentist suggested using ___expanders to adjust my teeth alignment.

这台电脑可以安装硬盘扩展器来增加存储空间。

This computer can install hard drive ___expanders to increase storage capacity.

在拓扑学中，扩张算子用于将几何空间放大到更高维度。

In topology, ___expanders are used to enlarge geometric spaces into higher dimensions.