These cloud formations were seen over the western aleutian islands .

这个云的形成是在阿留申群岛西部看到的。

On the basis of causes of formations of learning motivation , we can divide it into interior and exterior learning motivation .

依据学习动机形成的原因，可分为内部学习动机和外部学习动机。

The result is a collection of 40 images of deserts , deltas , glaciers , cloud formations , mountains , valleys and coastlines where light is the medium and not paint .

这些是40张关于沙漠，三角洲，冰川，云的形成，山脉，峡谷，海岸线等地方的合集，在那里，光只是媒介而不是描绘者。

Over the centuries , people have tried everything from the behaviour of animals and unusual cloud formations to the water level in wells and the phases of the moon to predict earthquakes .

几个世纪以来，人们千方百计预测地震，从动物行为和不同寻常的云的形成，到井水的水位和月亮的周期。

Water and plants , it seems , fit the bill nicely . Each is essential to the development of tiger-bush formations . Each tends to spread : water by seeping across the soil ; plants by ejecting seeds or spores .

水和植物貌似很好的吻合了这些要求，他们都是虎斑灌木形成的必要条件，他们也都可以传播散布：水通过渗透土壤，植物通过洒下种子或孢子。