where giant land masses are pulling away from one another. 巨大的陆地板块在此互相分离
one of the lowest hottest places on Earth. 地球上一处最低最热的地方
and encourages the herd to make one last effort. 它鼓励象群再做最后的努力
Three dogs close in on one impala. 3只野狗紧追一只黑班羚
Deserts cover one third of the land's surface 沙漠覆盖了地球表面的1/3