When you compare the prices,you must take everything into consideration.
当你在考虑对比价格时,首先必须把一切都要考虑进去。
And why only snakes? Cats, for instance, would be greatly helped; no running fights with large, fierce rats or tussles with grown rabbits -- just a bite and no more effort needed.
为什么只有蛇才有毒液呢?譬如说,如果猫有毒液,那对猫会大有帮助,它就不必再和又大又凶的老鼠边跑边博斗了,也不必再和大兔子扭斗了,只要咬一口,就不必再费大力气。