Prf
n. pulse-repetition frequency的简 写
🗣️ 情景例句
We don't get to see enough of each other.
我们在一起的时间太少了。
Finally,I asked him how old he was.
最后,我问他他多大。
Were you in San Francisco at the time of the big earthquake in 1989?
1989年旧金山大地震时，你在那儿吗？