EX15: Chọn đáp án đúng 21: You can turn off the radio. I (not listen) to it. A. don't listen B. am not listening C. didn't listen D. Won't listen 22: Where (you / have) dinner yesterday? A. did you have B. do you have C. are you having D. Have you had 23: This exercise is difficult. I (help) you to do it. A. help B. am helping C. helped D. Will help 24: What (you / cook) tonight? A. are you going to cook B. do you cook C. are you cooking D. Have you cooked 25: (you / finish) your homework yet? A. did you finish B. do you finish C. have you finished D. Will you finish 26: My father (go) to the bank. He'll be back soon. A. went B. gone C. has gone D. Have gone 27: What (they / do) at 9.00 last night? A. did they do B. are they doing C. have they done D. Were they doing 28: It (snow) when we (leave) the library. A. was snowing – left B. was snowing – leave C. snowed – left D. Is snowing – is leaving 30: My cousin is a writer. He (write) three novels. A. write B. writes C. wrote D. Has written