However, this WSDL file, or the contract, does not declare which element (s) may be a required or optional variable for the invocation.

然而，WSDL文件，或者说协议并没有指明哪一个元素是调用服务必须的或可选的变量。

youdao

Optional ships will be considered part of same series of sister vessels if the option is exercised not later than 1 year after the contract to build the series was signed.

选择权船舶将被认为属于系列姐妹船的一部分，条件是其选择权在系列船舶合同签署之后1年之内生效。

youdao

Optional ships will be considered part of same series of vessels if the option is exercised not later than 1 year after the contract to build the series was signed.

选择权船舶将被认为属于系列船的一部分，条件是其选择权在系列船舶合同签署之后1年之内生效。

youdao