Thiophanthrene
萘并[2, 3-b]噻吩
🗣️ 情景例句
But Dad is always so busy.
但是爸爸总是那么忙。
Step after step the ladder is ascended.
按部就班，循序渐进。
One day a letter from my father arrived at the school, asking for a teacher for me.
有一天，我父亲的信寄到学校，请求为我聘用一名教师。