名词
中文翻译：有效期限
同义词：
['validity period', 'validity range例句：1. The contract has a valid period of three years.（这份合同的有效期限为三年。）2. We need to check the validity period of the passport before leaving.（在离开前，我们需要检查护照的有效期。）']
例句：
-
1. The contract has a valid period of three years.
这份合同的有效期限为三年。
-
2. We need to check the validity period of the passport before leaving.
在离开前，我们需要检查护照的有效期。
-
3.The product is only valid within the validity period.
该产品仅在有效期内有效。