Find and correct the mistakes. Two of the sentences are correct.

Here are the corrected sentences: 1. She shouldn't worry about earning more money - she's already so well-off! (Correct) 2. You mustn't be afraid of spiders - they can't hurt you! (Incorrect) Corrected: You don't have to be afraid of spiders - they can't hurt you! 3. I work full-time, so I must to be very well-organised. (Incorrect) Corrected: I work full-time, so I must be very well-organised. 4. He should study German - he has no talent for languages. (Correct) 5. You mustn't tell anyone - it's a secret. (Correct)