選擇題要解析
When( ),the new stadium will hold 50000 people.
A completed B be completed C compleing D having completed
答：A
譯：新的體育館落成時(shí),將能容納五萬觀眾.
析：when completed=when it (=the new statium) is completed,有兩種說法：
1.
狀語從句省略主+be：如上所示,當(dāng)狀語從句中的主語=主句主語且謂語中有be動(dòng)詞時(shí)（不論是系動(dòng)詞還是助動(dòng)詞）,可以省略"主+be"
2.
分詞前+連詞說：分詞作狀語,可以是時(shí)間、條件、原因、讓步等等,具體看句子的邏輯判斷.如需要明確,可以在前加上連詞.如本句,如為：Completed,the new stadium will hold 50000 people.中的completed,可以理解成時(shí)間狀語,也可以理解成條件狀語,加個(gè)when或if,則句意明了,也避免了單個(gè)的過去分詞作狀語,太顯單薄.