1: have you ever met-sit

2. Did you star- recently competed -asked

3. Saw- have already seen 

4. Has worked-started 

III.

1. A (sửa: did)

2. B (sửa: haven't made)

3. A (sửa: has learned)

4. B (sửa: has gone out)

5. B (sửa: met)

6. A (sửa: bought)

7. B (sửa: has been)

1. A : Have you ever met

    B : sat

2. A : have you started

    B: have recently completed - asked

3. A : saw

    B : have already seen

4. A : has worked 

    B : started

III. Circle the mistake and then correct it 

1. A . has done → did

2. B . didn't make → haven't made 

3. A . learned → has learned 

4. A . has finished → finished

5. B. have met → met

6. A . has bought → bought 

7. B. was → has been