1. Let's do it, it's worth a shot. I think global warming is worth mentioning at this conference. It's not worth arguing over a broken vase. This house is worth £2 million, we can't afford it. 2. This soil is rich in important minerals. Britain is rich in its historic places. Dairy products are rich in calcium. Saudi Arabia is rich in oil. 3. I am so tired of my boring job, I am going to look for a different job. She was tired of waiting for him to call so she called him first instead. I am sick and tired of hearing about politics. Don't you feel tired of people telling you what to do? 4. I've collected so many points at Starbucks that now I can get a free drink. She barely gets any free time, she is constantly working. Many high-end make-up stores give you free samples of cosmetics to try before you make a decision to buy it. The doctor is free now, he will call you in shortly.