В каких предложениях, необходимо использовать Infinitive: We regret (tell) you that you have failed this exam. He regrets (make) that mistake; now he doesn’t have money. Bob was sorry for (shout) at his little sister. They went on (discuss) this question for hours. I’m sorry (interrupt), but can I ask you something?

I for one have a lot of friends. They are people who I can have great fun with. When I am in trouble they're always there to cheer me up. Let's take Jack, for example. He's the one who I can turn to when I have problems at home. I can talk all my problems through with him. He's supportive and can keep secrets. It's important, isn't it? And Jane? She's so brainy! I always turn to her when I have problems with maths.
Jessica is great at working on the computer. She teaches me how to work, too. She's so kind and considerate. We have a lot of similar interests with Mike. And besides Mike is the only one I can play football with! Each time we all get together we have a good laugh. Sometimes we have arguments but we make up (миримся) quickly. We are never bored.