Polyacetylene
聚乙炔
🗣️ 情景例句
Hello. This is Richard Stewart.
你好， 我是Richard Stewart。
Did you go camping this morning?
你今早去露营了吗？
but Captain Fawcett did not take him because the trip was too dangerous.
弗西特机长之所以不送他去，是因为那段飞行太危险了。