Polyacetylene
聚乙炔
🗣️ 情景例句
By plane?
坐飞机来？
My country is rich in natural resources.
我国自然资源丰富。
The early climbers were looking for the easiest way to the top, because the summit was the prize they sought, especially if it and never been attained before.
早期登山者所寻找的是通往山顶的最方便的途径，因为顶峰特别是前人未曾到过的顶峰 -- 才是他们寻求的目标。