From there, they use natural updrafts, also called mountain waves, to soar to the sky.

之后，飞机将利用上升气流飞翔，人也把他叫作“地形波”。

We're leaving here on the warm updraft.

“在乘着这温暖的上升气流离开这里。

Battling violent updrafts and acid clouds, these non-stick pioneers were swept nearly halfway round the planet.

对抗着上升气流和酸云, 这些不为人知的先驱者已经几乎环绕这行星一周。

The more condensation and the bigger the storm clouds grow, the more powerful those updrafts become.

凝结程度越大，并且形成风暴的云团越大时，那些上升气流也就越强。

The baby spiders felt the warm updraft.

蜘蛛觉到温暖的上升气流。

The baby spiders felt the warm updraft. One spider climbed to the top of the fence. Then it did something that came as a great surprise to Wilbur.

小蜘蛛受到了这温暖的上升气流。一只蜘蛛爬到了栅栏上面，然后他做了件令威伯非常惊奇的事。

For instance, stratus clouds-those unlovable, featureless sprawls that give us our overcast skies, happen when moisture-bearing updrafts lack the oomph to break through a level of more stable air above, and instead spread out, like smoke hitting a ceiling.

比如，要是携带水汽的上升气流无法突破上面比较稳定的一层空气，就会像烟碰到了天花板那样向外展开，于是就形成了层云一那种不大讨人喜欢，毫无特色，弄得天空阴沉沉的云层。