Praetrsonics
极超短波晶体声学, 特超声(学)
🗣️ 情景例句
Welcome to China. May I have a look at your customs declaration?
欢迎来中国。我可以看一下您的入境申请报表吗？
Fill it up with unleaded and check the oil,please.
请加满不含铅的汽油，并检查一下机油。
It looks as if she's gone away for a few days.
好象她要外出好几天了。