THE DOG……….THE CAT BEFORE WE COULD SAVE IT. A. HAS KILLED B. WAS K...

21. - KIEM TRA 1 TIET SAU UNIT 3
KIEM TRA 1 TIET SAU UNIT 3
21. The dog……….the cat before we could save it. a. has killed b. was killing c. had killed d. will kill