Piperylene
戊间二烯
🗣️ 情景例句
and how hard it is
他还说这件事很难
Here's no necessary.
我看没这必要。
From these he can go on to appreciate more complex forms or combinations of several forms.
从这些形体出发，观赏者可进一步观察更为复杂的形体或若干形体的组合。