参考答案

正确答案：D
解析：本题考查until的用法。until在否定句中，表示“直到……才”，“在……前”的意思。如：I did not see Papa until the evening．(直到晚上我才见到爸爸。) It is not until...that...是强调句型。如：It was not until I had read your letter that I knew the truth．(直到读了你的信，我才了解真相。)