Here are the correct answers for the exercises:

**Exercise 1: Circle the correct answer**
1. Police **catch** robbers.
2. My dad is a driver. He always **wears** a white coat.
3. They never **drink** drinks beer.
4. Lucy **goes** window-shopping seven times a month.
5. She **has** a pen.
6. Mary and Marcus **eat** out every day.
7. Mark usually **watches** TV before going to bed.
8. Maria is a teacher. She **teaches** students.

**Exercise 2: Fill in the blanks with "don't" or "doesn't"**
1. I **don't** like tea.
2. He **doesn't** play football in the afternoon.
3. You **don't** go to bed at midnight.
4. They **don't** do the homework on weekends.
5. The bus **doesn't** arrive at 8:30 a.m.
6. My brother **doesn't** finish work at 8 p.m.
7. Our friends **don't** live in a big house.
8. The cat **doesn't** like me.

**Exercise 3: Fill in the blanks with present simple**
1. She **doesn't study** on Saturday.
2. He **has** a new haircut today.
3. I usually **have** breakfast at 6:30.
4. Peter **doesn't study** very hard. He never gets high scores.
5. My mother often **teaches** me English on Saturday evenings.
6. I like Math and she **likes** Literature.
7. My sister **washes** the dishes every day.
8. They **have** breakfast every morning.