There is no denying that...Only in this way,can we..情况,which is becoming more and more serious.First of all/Above all,what's more,The last but not the least.第一第二第三.前面几个是高级句式...不能否认。。。不用太多难句式，作文也就12句，用3-4巨难的就行了，注意用高级词汇，别good，very还高三写注意条理清晰，第一第二第三一定写，长短句穿插写就行了。