如果症状复发，你必须去看医生。

You must see a doctor if the symptoms ___return.

她冷静下来后，信心慢慢恢复了。

After she calmed down, her confidence slowly ___returned.

在经历了长期的困难之后，乐观的感觉又开始出现了。

The feeling of optimism began to ___return after a long period of difficulty.