1. He is in a blue mood today.

2. She looks so blue.

3. I've got the blues today.

4. It's depressing.

5. No one understands me. It's depressing.

6. Don't talk like that! I'm feeling blue.

7. Blue Monday is really depressing after a wonderful weekend.

8. He felt blue after the argument.

这些句子展示了“blue”这个词在不同语境下如何用来表达忧郁或沮丧的情绪。