Change into negative without changing the meaning

Rewrite the following affirmative sentences as negative sentences without changing their meaning.
Note that this might involve replacing a word with its antonym. Sentences containing words like never are treated as negative sentences.

1. Stella is prettier than Mary.

2. Jack always agrees to help his friends.

3. He drives his car very carefully.

4. They have accepted the invitation for the party.

5. Very few children participated in the program.

6. A fox is cleverer than a jackal.

7. This shop only sells expensive articles.

8. She always keeps her room tidy.

9. He is polite to everyone.

10. He is very industrious.

Answers

1. Mary is not as pretty as Stella.

2. Jack never refuses to help his friends.

3. He does not drive his car carelessly.

4. They have not refused the invitation for the party.

5. Not many children participated in the program.

6. A jackal is not as clever as a fox.

7. This shop does not sell cheap articles.

8. She never leaves her room tidy.

9. He is not rude to anyone.

10. He is not lazy.