Louise was listening to the radio while she ……………… the house.
A. is cleaning
B. was cleaning
C. had cleaned
D. will dean
Câu trả lời là: B là đáp án đúng
Công thức nguyên hàm và tích phân
Louise was listening to the radio while she ……………… the house.
A. is cleaning
B. was cleaning
C. had cleaned
D. will dean
Câu trả lời là: B là đáp án đúng