lightn.光；光线；灯；打火机；领悟；浅色；天窗adj.轻的；浅色的；明亮的；轻松的；容易的；清淡的v.点燃；变亮；照亮adv.清楚地；轻便地light bar光条

1. The cracking of light alkanes is much difficult in comparison with that of petroleum fractions.
   低碳烷烃裂化比石油馏分困难得多。