Niobyl
铌氧基
🗣️ 情景例句
Those are the rules and regulations, and we have to abide by them.
这些就是这儿的规矩， 大家都应该遵守。
It is the first step that costs.
万事开头难。
Visitors have been asked to keep the woods clean and tidy.
游客已被告知要保持树林的整洁。