Of course, these reasons are valid2 and motivate3 us to bury our heads in thick language textbooks and repeat after a monotonous4 voice on an audiocassette.

• 当然，这些原因是确实的，激发我们的学习积极性，埋头于厚厚的语言教科书，并跟着盒式录音带重复单调乏味的语声。