Ответ:

  1. Some people would think it’s a bit loud, but I love bright colours!
  2. The company uses tests to identify the brightest people to employ.
  3. It’s hard to know when you’re joking.
  4. He has to wear a smart suit to his brother’s graduation ceremony.

Ответ: 1 loud; 2 brightest; 3 hard; 4 smart.