base period造句

1、The contract performance covers a 6 month base period with four one-year option periods.
合同日期包括6个月的基本期和四个为期一年的选择期。

2、The contract has a four-month base period and three one-year options.
该合同有一个4个月的基本期和3个一年的选择。

3、The contract includes a base period of five years with one five-year option.
该合同包括一个5年的基本期和一个5年期选项。