英语语法分析

Its main components include propane butane and butylene.

主要成份是丙烷、丁烷、丁烯等。

Its main components include propane, butane and butylene.

主要成份是丙烷、丁烷、丁烯等。

Propylene and butylene yields increase with low hydrogen transfer reaction.

氢转移反应越低，丙烯及丁烯等烯烃选择性越高。