Pentone
缬烯炔, 异戊烯炔
🗣️ 情景例句
What will the monthly payments be?
每月要付多少？
Do you ever go swimming on the weekend?
你曾经在周末去游泳吗？
The clouds had come down so suddenly we had no warning.
乌云突然出现，我们丝毫没有觉察。