我的衬衫掉了一颗纽扣。

A ___button fell off my shirt.

点击保存按钮来存储你的文件。

Click the ___Save ___button to store your file.

她在背包上别了一枚环保组织的徽章。

She pinned an environmental group's ___button on her backpack.

她匆忙地扣上了外套的纽扣。

She quickly ___buttoned up her coat.