Heptacene
[化] 并七苯
🗣️ 情景例句
It's nice to be alone with you, Grandpa.
很高兴单独与你在一起， 爷爷。
Did you go to the circus last night?
你昨晚去看马戏了吗？
for fear the agents of other firms should be able to trace the kind of research they are likely to be undertaking.
他们生怕别的公司的情报人员据此摸到他们可能要从事的某项科研项目。