a. experiencing or marked by or causing sadness or sorrow or discontent
s. causing discomfort
a. 不快乐的, 不幸的, 不适当的
1. She felt unhappy when her friend moved away.
当她的朋友搬走时，她感到不快乐。
2. It's normal to feel unhappy sometimes.
有时候感到不快乐是正常的。
3. He tried to cheer her up because he didn't like to see her unhappy.
他试图让她开心，因为他不喜欢看到她不快乐。