Case studies are an integral part of knowledge cumulation. 案例研究是知识累积的主要部分。
Other things followed from time to time, little things of the same sort, which in their cumulative effect were eventually equal to a full revelation. 此后又不断地发生了其它一些事情,同样性质的小事情,这些事情累积起来,最终的效果是给人以充分的启示。