License system
[经] 签证制
🧩 词语组成解析
🗣️ 情景例句
How much does it cost?
这得花多少钱？
I wish to express my gratitude to you for your cooperation.
我要对你的合作表达感激之意。
it must be known to any kind of radio astronomer in the universe.
这个频率是宇宙中任何射电天文学家都应该熟悉的。