Thiirene
[化] 硫雜丙烯環
??? 情景例句
They have to be here.
它們肯定就在這兒。
She's off to Guangzhou tomorrow.
她明天出發去廣州。
As a reasonable guess, they might, on an average, be 100 light years away.
據合理推算，外星人離我們平均距離也有100光年之遠