Ifdef
n. 如果定义了
🗣️ 情景例句
Please keep off the grass.
请勿践踏草地。
Teaching others teaches yourself.
教学相长。
For a whole week I did not smoke at all and during this time, my wife suffered terribly.
整整一个星期我根本没有吸烟。在此期间，我妻子吃尽了苦头。