EAP 140 PM - WANG, Lingshan - Week 6 1/4

   When we want to join independent clauses with coordinating conjunction, we should put comma before coordinating conjunction.
   e.g.  We are too young to solve this problem, and we don't know who we can trust.
   We should use comma after an introductory clause or pharse
   e.g.  When I go to school, my mom stays at home and does some housework.
   We should put a comma between all terms in a series.
   e.g.  He is a talent who is good at everything, including math, language, and music.
   For the biological cause, there is a material in some addicted people called “dopamine”.

Their parents like to use drugs or drink, they have bad gene.