W选择题要解析When( ),the new stadium wil hold 50000 people.A completed B be completed C compleing

选择题要解析
When( ),the new stadium will hold 50000 people.
A completed B be completed C compleing D having completed
答：A
译：新的体育馆落成时,将能容纳五万观众.
析：when completed=when it (=the new statium) is completed,有两种说法：
1.
状语从句省略主+be：如上所示,当状语从句中的主语=主句主语且谓语中有be动词时（不论是系动词还是助动词）,可以省略"主+be"
2.
分词前+连词说：分词作状语,可以是时间、条件、原因、让步等等,具体看句子的逻辑判断.如需要明确,可以在前加上连词.如本句,如为：Completed,the new stadium will hold 50000 people.中的completed,可以理解成时间状语,也可以理解成条件状语,加个when或if,则句意明了,也避免了单个的过去分词作状语,太显单薄.