About Trees

About Trees, written by Sherry Sterling.

《认识树木》，谢里·斯特林 著

Introduction. Trees are the tallest living plants. Redwood trees can grow as tall as a 30 story building. Giant sequoias can weigh as much as 3 ,000 large pickup trucks, making them one of the heaviest living things. Trees also live a long time. Many trees alive today were full grown long before the United States became a country. But these massive trees share something with all plants. They make their own food.

引言 树木是现存最高的植物 红杉能长到三十层楼那么高 巨杉的重量相当于三千辆大型皮卡，是地球上最重的生物之一 树木的寿命也很长 现在存活的很多大树，早在美国建国前就已经完全长成了 但这些巨树和所有植物有一个共同点 它们可以自己制造养分

Leaves. Imagine being able to make your own food without cooking or even going to a restaurant. Leaves make food for trees by changing energy from sunlight into food. This important work is done by chlorophyll, the green coloring in leaves. Leaves come in all shapes and sizes. Most deciduous trees have wide, thin leaves, while most conifers have needle -like leaves. Conifers keep their needles through all seasons. Only the oldest needles fall to the ground. Desiduous trees lose their leaves every fall.

树叶 想象一下，你不用做饭、也不用去餐厅，就能自己做出食物 树叶把阳光转化为能量，为树木制造养分 这项重要工作由叶绿素完成，它就是树叶里的绿色色素 树叶有各种各样的形状和大小 大多数落叶树长着宽大轻薄的叶子，大多数针叶树的叶子像针一样 针叶树一年四季都长着针状叶 只有最老的针状叶才会脱落到地上 落叶树每年秋天都会落叶

In the fall, the leaves of deciduous trees show their true colors. These true colors are yellows, oranges, and browns, which hide under green chlorophyll all spring and summer. We see these colors in the fall after leaves stop making chlorophyll.

到了秋天，落叶树的叶子就会露出它们真正的颜色 这些真正的颜色是黄色、橙色和棕色，整个春天和夏天它们都藏在绿色的叶绿素下面 叶子停止制造叶绿素后，我们就能在秋天看到这些颜色了

Branches. Branches are the arms that hold up a tree's leaves. Branches spread leaves out to get as much sunlight as they can. The leaves give shade to other living things on sunny days. Branches start out as twigs. Then they grow thicker each year. As a tree grows, its bark cracks open so the branches and trunk can expand. New bark is always growing under the old, ready to protect the tree. If new bark gets stripped away, a tree can die.

树枝 树枝就像树木的手臂，托着所有的树叶 树枝把树叶展开，好让它们尽可能多地吸收阳光 晴天的时候，树叶还能给其他生物遮荫 树枝最开始只是小嫩枝 之后每年都会长粗一点 树木生长的时候，树皮会裂开，让树干和树枝有空间变粗变大 新的树皮一直在老树皮下面生长，时刻保护着树木 如果新树皮被剥落，树木就可能死去

Trunk. Tubes in the tree's trunk carry water from the roots up to the leaves. They also carry sap, or food, down from the leaves to the roots. These tubes are like highways, carrying traffic back and forth. They are close to the outside of the tree, just under the bark.

树干 树干里的导管把水分从根部运送到树叶 它们也会把树液也就是养分，从树叶运送到根部 这些导管就像公路，来回运输着养分 它们靠近树木的外层，就在树皮的下方