为了保持最佳品质应该每年或一年半更换一次罐头食品。

For optimum quality, however, replace canned goods every year to year-and-a-half.

youdao

形体小的鸟儿一年脱羽一到两次。它们有9到10只主要用于飞行的羽毛，鸟儿们一次更换几只，在几周的时间内它们就可以完成更换。

Small birds molt once or twice a year, and they replace their 9 or 10 primary flight feathers a few at a time over the course of a few weeks.

youdao

形体小的鸟儿一年脱羽一到两次。它们有9到10只主要用于飞行的羽毛，鸟儿们一次更换几只，在几周的时间内它们就可以完成更换。

Small birds molt once or twice a year, and they replace their 9 or 10 primary flight feathers a few at a time over the course of a few weeks.

youdao