Normal vibration
[化] 简正振动
🧩 词语组成解析
🗣️ 情景例句
The times have been very bad.
时机一直很坏。
My aunt will come to live with me for some days.
我阿姨会来和我住一些日子。
But here we come up against the most difficult of all obstacles to contact with people on other planets ----the astronomical distances which separate us.
然而，在和外星人联系中我们遇到的最大困难是分隔我们的天文距离。