“分子团”的英语？

内燃机的工作原理是将汽油中分子团的能量转化为动能.Internal combustion engines convert the energy in gasoline's molecular bonds into motion.含氧量: 经远经外辐射水中大分子团变小分子团, 并使游离氧增加.Oxygen Content : Radiated by far - infrared, big molecule turns into ...