that contains vital minerals scarce in their natural diet. 而这种矿物质很难从自然食物中获取
This herd contains calves, easier targets. 这一象群里有更容易下手的幼象
400 miles long and over a mile deep, Baikal contains one fifth of all the fresh water found in our planet's lakes and rivers. 贝加尔湖长400英里 深度超过1英里 其中淡水储量占到了全球江河湖泊淡水总量的1/5
but it contains more than 50 percent of all its plants and animals. 但其中的动植物种类却占到了全球的50%
contains a third of all the trees on Earth 容纳了地球上1/3的树木