Backstepping
n. 逐步退焊法\\nv. 往后退（backstep的ing形式）
🗣️ 情景例句
I'll wait for my father.
我要等我爸爸。
That street is only two miles long.
那条街仅仅是2英里长的。
The most economical age to capture an elephant for training is between fifteen and twenty years,
捕捉15至20岁之间年龄的大象进行驯练最为经济。