lightfaced

例句：

1. 1. She always has a lighthearted smile on her face.
   她总是面带微笑。
2. 2. The children were lighthearted in their conversation.
   孩子们在交谈时面带和蔼。
3. 3. He was lighthearted about the upcoming meeting.
   他对即将到来的会议面带友好。