4 Complete the sentences with the comparative form of these adjectives. difficult • intelligent • relaxed responsible • serious • stressful

1. The life of a teenager these days is more stressful than in the past. They have a lot more things to worry about.
2. I think a dog is more intelligent than a cat. They can understand when you talk to them.
3. He looks more relaxed than his brother, but he is very good fun.

*Объяснение:*
В этих предложениях нужно использовать сравнительные формы прилагательных, чтобы показать сравнение между двумя объектами или ситуациями. Так как прилагательные длинные, используем "more" перед ними.