我觉得你写不够2分钟的原因是你没有用主题句+具体例子的办法.在托福雅思等口语考试中,不能只是笼统地概括你要说的东西,必须给出细节.按照这个思路,你应该能很容易地写出长度为2分钟的文章.
我以第四题为例.
Well,for students who are afraid fo speaking English in front of other people,I have suggestions as following.
Firstly,they should practise speaking English hard everyday.The reason why students are afraid of speaking English in public is mostly that they can't speak English well.You know,pratice makes perfect.Students should improve their level of English by a lot of practice.Only by doing this can they build confidence in speaking English.
Secondly,others' encouragement and praise are always the best motivation for students to move on.Therefore,students should make every effort to create chances to obtain others' praise by speaking English.For example,you could prepare a topic about sports very well in advance.And then you could talk about this topic with other people in an English corner.Because of good preparation,you can speak English very well and others will speak highly of your English.That way,you will become very confident.
Thirdly,before speaking in front of people,you can practice in front of a video camera to get ready.You could do it over and over again until you get it perfect,which will help you perform better when facing audiences.
我觉得已经超过2分钟了~只要加入适当的细节~就容易啦~加油~:)