retractable fibre

例句：

1. 1. This retractable umbrella is very convenient to use.
   这款可伸缩雨伞使用起来非常方便。
2. 2. The retractable roof can be opened and closed quickly.
   可伸缩的屋顶可以快速打开和关闭。
3. 3. The retractable pen is a great tool for writing.
   可伸缩的笔是写东西的好工具。