题目

Not until ______from work at about 12 a.m. did the children stop making noise. A. he came back            B. came he back    C. would he come back      D. did he come back 答案：A小红拿一个长方形（）的木框在阳光下玩，长方形木框在地面上形成的投影如图所示：不可能形成的投影的是________．（填序号）