Optical constants
[电] 光学常数
🧩 词语组成解析
n. 常量, 常数；物理常数（constant的复数）
🗣️ 情景例句
That's alright. You're a lot of help.
没关系。你帮了很大的忙。
I doubt it.
我表示怀疑。
As there are so many people about, the dogs have to be kept in a special enclosure.
由于来人太多，狗被关在专门的围栏里。