大家帮我分析一下英语题!!

At the upper timberline the trees begin to become twisted and deformed.

在上面的树带界线那树开始变成反常的和不成形的。

This is particularly true for trees in the middle and upper latitudes, which tend to attain greater heights on ridges, whereas in the tropics the trees reach their greater heights in the valleys.

这特别地真实对树在那中央和上面的纬度,容易在脊上达到较棒的高度, 然而在回归线中树延伸他们的较棒的高度在山谷中。

This is because middle- and upper- latitude timberlines are strongly influenced by the duration and depth of the snow cover.

这是因为中央- 和上面- 纬度树带界线强烈地影响在期间之前和雪的深度掩护。

As the snow is deeper and lasts longer in the valleys, trees tend to attain greater heights on the ridges, even though they are more exposed to high-velocity winds and poor, thin soils there.

当做那雪是深的而且持续比较长的在山谷中, 树容易在脊上达到较棒的高度, 即使他们多暴露的对高速度风和贫穷的, 瘦的在那里弄脏。

In the tropics, the valleys appear to be more favorable because they are less prone to dry out, they have less frost, and they have deeper soils.

在回归线中，山谷似乎是更有利的因为他们较不倾向于干外面的, 他们有较少的霜, 和他们有深的土壤。

There is still no universally agreed-on explanation for why there should be such a dramatic cessation of tree growth at the upper timberline.

仍然有没有普遍地同意 - 在解释上为为什么应该有如此的一个戏剧性的停止树生长在上面的树带界线。

Various environmental factors may play a role.

各种不同的环境因素可能游戏一个角色。

Too much snow, for example, can smother trees, and avalanches and snow creep can damage or destroy them.

太多下雪水于, 举例来说, 能喘不过气树, 和雪崩和雪爬能损害或者破坏他们。

Late-lying snow reduces the effective growing season to the point where seedlings cannot establish themselves.

迟-说谎雪扼要减少有效的成长季节，于此苗木不能够建立他们自己。

Wind velocity also increases with altitude and may cause serious stress for trees, as is made evident by the deformed shapes at high altitudes.

也转动速度增加与高度和可能因素严重的压迫力为树, 如同是制造显然的被那不成形的形状在高海拔。

Some scientists have proposed that the presence of increasing levels of ultraviolet light with elevation may play a role, while browsing and grazing animals like the ibex may be another contributing factor.

一些科学家有被提议的出现逐渐增加的水平紫外线的光与海拔可能游戏一个角色, 当浏览的时候和放牧像野生山羊的动物可能是另外的有助于因素。

Probably the most important environmental factor is temperature, for if the growing season is too short and temperatures are too low, tree shoots and buds cannot mature sufficiently to survive the winter months.

或许最重要环境的因素是温度, 为如果成长的季节太短和温度太低点, 树芽和芽不能够成熟的充分地幸存冬天月。

Above the tree line there is a zone that is generally called

上方树线有一个地域哪一通常是呼叫

The temperature at the upper timberline is probably more important in preventing tree growth than factors such as the amount of snowfall or the force of winds.

温度在上面的树带界线或许更重要在避免树生长方面超过因素如此的当做大量的降雪或那力量风。