A leopard cannot run as fast as a cheetah和A leopard cannot run as fast as a cheetah runs的意思一样,那么后面这个runs可以去掉。
A leopard cannot catch a wildebeest as fast as a cheetah和A leopard cannot catch a wildebeest as fast as a cheetah catches的意思不一样,那么后面这个catches不仅不可以去掉,还要补充全。