Mesulphen
二甲基硫蒽
🗣️ 情景例句
Years of work went into these pictures.
多年心血换来这些照片。
Please come in; you're right on time.
请进，你正好准时到来。
Once the oxygen content of the air had risen to 25% it was ready to burn.
一旦氧气在空气中的含量达到25%，它就要燃烧。