分类：教育/科学-学习帮助
问题：一道选择题Look!Lindamadeamistakeinher 
Look!da made a mistake in her homework,I think it is a ___ mistake among the students.A.common   B.ordinary
回答：This is dumn easy.选common,因为前面的是a,不是an，如果是an，就选ordinary.