1、The contract performance covers a 6 month base period with four one-year option periods.
合同日期包括6個月的基本期和四個為期一年的選擇期。

2、The contract has a four-month base period and three one-year options.
該合同有一個4個月的基本期和3個一年的選擇。

3、The contract includes a base period of five years with one five-year option.
該合同包括一個5年的基本期和一個5年期選項。

4、The system uses base period wages to calculate MBA.
系統(tǒng)使用基本工資周期來計算MBA。

base period翻譯