A or B题型套路：
When we.../you，we.../you will be faced with the choice between A and B.Before making the right choice，we/you had better make a close comparison and contrast of them.
First of all，A...Also，B...Second，A...Likewise ，B...Despite their similarities， A and B are also different in the following aspects.First，A...However，B...Besides，A...On the contrary，B...
Therefore，it depends which...we/you should choose，If we/you...，we/you should choose A;but if we/you...，we/you should turn to B.
【范文】 Traveling by Train or by Plane
When we go on a business trip，we will be faced with the choice between traveling by train or by plane.Before making the right choice，we had better make a close comparison and contrast of them.
First of all，a train will take us to our target railway station.Also，a plane will take us to the target airport.Second，in a train we can enjoy the beautiful scenery of the countryside.Likewise，in a plane we can command a good view of fields，buildings，mountains and even clouds below.Despite their similarities， traveling by train or by plane are also different in the following aspects.First，a train ticket is less expensive.Most of us can afford it.However，a plane ticket is about twice as expensive as a train ticket.Most of us grudge paying for it.Besides， it is safer to travel by train.If the train gets into trouble，we may survive by jumping out of it.On the contrary，if we travel by plane，we have to ask God to bless us.Finally，it takes us longer time to travel by train than by plane.
Therefore，it depends which transportation tool we should choose.If we just want to save money，we will travel by train;but if we want to save time，we should turn to the plane.