to ensure that it is always available to meet our every demand. 来确保有足够淡水满足我们的需求
The great whites are shrewd hunters and use whatever cover is available. 大白鲨是高明的狩猎者 会利用一切可能的掩护
to take advantage of every available niche. 充分利用一切可用资源
so when other food is scarce, these fruits are always available somewhere or other. 所以当其他食物缺乏的时候,无花果树仍然会有果实