Mark the letter A, B, C, or D that indicates the correct answer to each of the following questions.

Câu hỏi

Sam regretted ______ hard enough in his previous job.

A. not having worked

B. not to have worked

C. Working

D. having worked

Đáp án
A. not having worked

Câu hỏi thuộc Bài tập:

E11- GS- Unit 5- Practice 2