After Mrs. Trang had returned to her house from work, she was cooking dinner
Task: Mark the letter A, B, C or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.
(Chọn một trong bốn đáp án A, B, C, hoặc D có chứa lỗi sai ở mỗi câu sau).
1. After Mrs. Trang had returned to her house from work, she was cooking dinner.
A B C D