Backtracking
[计] 回溯法
🗣️ 情景例句
How much for a haircut?
理发多少钱？
Don't you think it's too formal?
你不觉得太正式了吗？
Excuse me, Mr. Hu. Can you look after my watch, please?
劳驾，胡老师，你能帮我保管一下我的手表吗？