He was stooping to pick up the pen.

他在弯腰捡笔。

Stooping for long periods can cause back pain.

长时间弯腰会导致背痛。

The gardener was stooping to tend to the flowers.

园丁在弯腰照料花朵。

He avoided stooping by using a long-handled tool.

他通过使用长柄工具来避免弯腰。

She noticed her grandfather stooping more as he aged.

她注意到她的祖父随着年龄的增长弯腰更多了。

Is the pain worse when straightening up ( stooping down )

当您伸腰（弯腰）时疼痛加重吗？

There is nothing so likely to give it as standing and stooping in a hot sun;

站在大太阳底下．，一会儿直腰、一会儿弯腰地剪花，最容易让人头痛。

I yearn , while stooping, for my homeland more.

低头思故乡.

Stooping to contemptible methods to realize their ambitions;

为实现他们的野心而卑屈到采取可鄙的手段；

Stooping down to pick up the pen, he felt a sharp pain in his back.

弯下腰捡笔时, 他感到背部剧痛.