问题
选择题
—I didn't go to see the doctor yesterday.
—But you________.
A．ought
B．ought to
C．oughted to
D．ought to have
答案
答案：D
从对话中可以看得出来,双方谈论的话题是过去的事,故应用ought to have +过去分词,省略时,则须在to之前加上have。错选B者主要是没注意到句中的yesterday,是表过去,而非现在。