我祖父总是把他的背心扣好。

My grandfather always wore his ___vest buttoned up.

确保船上每个人都有救生背心。

Be sure you have a life ___vest for each person in the boat.

毛衣背心是在凉爽天气叠穿的完美选择。

A sweater ___vest is perfect for layering in cool weather.