核心问题
You ____ waste your time. You ____ work hard at your lessons.
A. oughtn't ... ought to B. oughtn't to ... ought to
C. oughtn't to ... need D. oughtn't ... must
上题的正确答案为 B, 能否选 A 或 D 呢?
词典解答
上面的试题出得不大好,因为在美国英语里,否定句和疑问句中的 ought to 是可以省略 to 的,因此,选项 A 和 D 也是正确的,见上条。
ought to/must 用在间接引语中 见 must