no need for the jet propulsion used by it's shallow water relatives above. 不象它的浅海亲戚利用喷射水流的反作用力
Deep water plankton start to rise from the depths and another hungry army prepares to receive it. 深海的浮游生物开始浮上水面, 另一支饥饿的部队准备接受这些猎物
The dolphin scan the water ahead with their sonar. 海豚利用声纳扫描大海
enable it to soar through the water, with the least expenditure of energy. 可以让它花费很小的力量在水里巡游
patrolling the top one hundred meters of water. 巡游高度在海平面至水下100米之间
Taste in water, is the equivalent of smell in the air. 鲨鱼能在水中“闻”到各种气味
The dense shoals, on which so many depend gather only when water conditions are perfect. 只有在水况非常好的情况下 才会出现这样的鱼群聚集
Flush with water, the baobab prepares itself for an unforgettable display. 在水的作用下 波巴布树正在准备一场让人终生难忘的演出
and collect water to store in their huge trunks, ready for the dry season ahead. 用来收集水分并储存到巨大的躯干中 用以对付干季的到来
but the dry season is so severe that the trees can't afford to loose the amount of water that would evaporate from their broad leaves, 在炎热干燥的季节 树木无法承受水分从叶子上的大量流失