眼珠周围的虹膜呈现出美丽的琥珀色。

The ___iris around the pupil shows a beautiful amber color.

她在后院种了一些黄色的鸢尾花。

She planted some yellow ___irises in her backyard.

在弱光环境下拍摄时，你需要打开相机的光圈。

You need to open the ___iris of the camera when shooting in low light.