单词bird-s-mouth
Now use a small, soft-edged brush to get rid of the object in the bird"s mouth.
用一个小一点的软笔刷清除鸟嘴处的东西。
In bird banding work, the band must be put on first before measuring the bird"s mouth, wings, head, and so forth.
上网的鸟带回室内，要先上脚环，再测量鸟的嘴长、翼长和全头长等。
What is smaller than a humming-bird"s mouth?
什么比蜂鸟的嘴小？