相关知识点: 试题来源: 解析 Dad, could you tell me why leaves fall off trees in autumn? 1. 句子缺少主语,需要补充完整。 2. "leaf"是可数名词,根据句意应该用复数形式。 3. fall off 是固定搭配,表示“从……掉落”。反馈 收藏
Why Leaves Fall If you look around, you might find that leaves fall off the trees when winter arrives. Why is that? The short answer is that the leaves can't do their job any more. A leaf's job is to turn sunlight into "food" for the tree. To do this, the leaf needs water. ...
We all enjoy the colors of autumn leaves. The changing fall foliage never fails to surprise and delight us. Many areas in the United States are among the best in the world for leaf viewing, including New England, the Southeast, the Northwest and the Great Lakes regions. Find maps, dates,...
22. What do leaves turn into sugar? (不超过 5个词)Sunlight, CO2 and water.23. Why can some trees produce red leaves in autumn?(不超过10个词)Because sugar in the leaves can produce new colours.24. Why do leaves fall in autumn? (不超过 10个词)Because something special "cuts" the ...
Picking up leaves can pay off. Money may not grow on trees, but it does fall from them 鈥 right on schedule every autumn. At least that's the feeling of landscape contractors who offer leaf removal services. James Michael, owner of Landscape Solutions in Blue Ridge, V... P White - ...
aThe autumn is a leaf of front door, has not paid attention while the people, is opened quietly by the fall girl. 正在翻译,请等待... [translate] a老师告诉我们地球是圆的 Teacher tells us the Earth is round[translate] aI love you as my boyfriend,but you do not love me 我爱你作为我...
Autumn leaves seen through herbivore eyes Why leaves of some trees turn red in autumn has puzzled biologists for decades, as just before leaf fall the pigments causing red coloration are newly synt... Thomas F. Dring,Marco Archetti and Jim Hardie - 《Proceedings of the Royal Society B Biolo...
We all enjoy the colors of autumn leaves. Did you ever wonder how and why a fall leaf changes color? Why amaple1leaf turns bright red? Where do the yellows and oranges come from? To answer those questions, we first have to understand what leaves are and what they do. ...
autumn, the tree produces less and less chlorophyll. Slowly, the other colors which have been hiding in the leaves – red, yellow, or orange – are revealed. As autumn progresses, all of this pigment slowly deteriorates until only the brown tannins remain. Then the leaf dries and crumbles....
When a branch or even a stem is cut from a deciduous tree, why do the leaves stay attached to stems? http://en.wikipedia.org/wiki/Abscission Special cells attachdeciduous leavesto stems. In autumn, decreased sunlight triggers the production of chemicals that breakdown the walls of the attach...