What's the cheapest way to revive sterile earth where not even a blade of grass will grow, so that not only its grass returns, but crops may flourish as well? The answer is to let a few earthworms "run wild."
改良寸草不生的荒地，使其綠草如茵，甚或作物茂盛，最便宜的方法是什麼？答案是，「放生」一些蚯蚓。