英语翻译Only special plants can survive the terrible climate of

英语翻译
Only special plants can survive the terrible climate of a desert,for these are regions where the range of the soil temperature throughout the year can be over 75℃.Furthermore,during the summer there are few clouds in the sky to protect plants from the sun's rays.Another problem is the fact that there are frequently strong winds that drive small,sharp sands into the plants,tearing and damaging them.The most difficult problem for all forms of plant life,however,is the fact that each year the entire amount of rainfall occurs during a few days or weeks in spring.
Grasses and flowers in a desert survive from one year to the next by existing through the long,hot,dry season in the form of seeds.These seeds remain inactive unless the right amount of rain falls.If no rain falls,or if there is not enough rainfall,they wait until the next year,or even still the next.Another factor that helps these plants to survive is the fact that their life cycles are short.By the time that the water from the spring rains disappears - just a few weeks after it falls - such plants no longer need any.
The perennials (多年生植物) have special elements which enable them to survive as plants for several years.Thus,nearly all desert perennials have extensive root systems below ground and a small shoot (枝叶) system above ground.The large root network enables the plant to absorb as much water as possible in a short time.The small shoot system,on the other hand,considerably limits water loss by evaporation (蒸发).
Another characteristic of many desert perennials is that after the rainy season they lose their leaves as they prepare for the long,dry season,just as trees in wetter climates lose theirs as they prepare for the winter.This reduces their water loss by evaporation during the dry season.Then,in the next rainy season,they come fully alive once more,and grow new branches,leaves and flowers,just as the grasses and flowers in a desert do.