英语语法分析

Ten of them were identified. They are ethylene, propylene, isobutane, cyclobutane, three isomeric butenes, methyl ethyl ether, ethyl isopropyl ether, and ethyl acetate.

它们是乙烯，丙烯，异丁烷，环丁烷，丁烯类化合物三个，甲基乙基醚，乙基异丙基醚，乙酸乙酯。