The three major causes for errors are: mother tongue interference,（）,and inappropriate teaching materials or methods.

A（）is a set of procedures or a collection of techniques used in a systematic way which it is hoped will result in efficient learning. 点击查看答案

When we use the word（）we mean that an idea or theory is being applied: that whatever the teacher does, certain theoretical principles are always borne in mind. 点击查看答案