Mark the letter A, B, C, or D on your answer sheet to indicate the cor

Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.    

She was walking to the library to borrow some books when she was seeing a robbery.

• A. A. was walking
• B. B. the
• C. C. some
• D. D. was seeing

Hành động nhìn thấy kẻ cướp là hành động xảy ra trong khi hành động bước đi đang xảy ra => cần chia ở thì quá khứ đơn
=> D
Câu đúng: She was walking to the library to borrow some books when she saw a robbery.