We can never be satisfied as long as there is still one hard-working student who has to be in perplexity and search arduously for a similar exercise from a high stack of books.

只要还有一个勤奋刻苦的学生，在一堆厚厚的教辅书中翻来翻去、搔首踟蹰，费力地寻找那似曾相识的题目和解答，我们就绝不会满足。