Iff
[计] 如果仅仅, 当且仅当, \等价\
🗣️ 情景例句
Ten o'clock,
十点钟，
I get out of bed about 7 o'clock every morning.
我大约每天早上7点钟起床。
When it has been decided where we are going to drill, we put up at the surface an oil derrick.
当确定钻孔地点后，我们就在那里竖起一个井架。