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It's winter where I live…and a lot of trees have lost their leaves!
我居住的地方现在是冬天,许多树的叶子已经脱落了！
The leaves turned brown, or yellow, red, and even purple and then they fell off the trees.
叶子先变成棕色、黄色、红色甚至变成紫色，然后从树上掉下来。
But some trees are still green!
但是有些树仍是绿色的！
In fact, it seems like these trees don't ever turn brown—they stay green all of the time!
事实上，这些树叶似乎从未变成过棕色，它们的颜色一直都是绿色！
That's why we have a special name for these kinds of trees...evergreens!
因此这些树有个特殊的名称——常青树！
Depending on where you live, you might have some well-known evergreens in your neighborhood.
你可能会在住所附近发现一些著名的常青树。
These include pine, fir, and spruce.
这些树木包括松树、冷杉和云杉。
These trees are easiest to recognize by their leaves. And yes!
根据叶子识别这些树木很容易。是这样的！
Those thin, pointy, things on these trees are actually their leaves!
树上那些薄薄的、尖尖的东西确实是它们的叶子！
We usually call them needles, because that's what these leaves look like!
我们通常把它们称作针叶，因为那些叶子长的就像针一样！
Some needles are long and soft, and others are short and sharp.
有些针叶长而柔软，有些针叶短而尖锐。
When needles get old, they do fall from the tree, but usually just a few at a time,
当针叶变老后，它们会从树上落下来，但通常一次只会落下一些，
and the tree grows new ones very quickly.
并且新的叶子很快就能长出来。
So the trees stay green all year round.
所以这些树全年都是绿绿的。
Now, even though needles don't look like the leaves on other trees,
虽然这些针叶看起来与其他叶子不一样，
they have the same job — to catch sunlight.
但是它们的功能是一样的——都能捕捉阳光。
The tree then uses the sunlight to make energy. And energy helps the tree grow!
树木利用阳光来产生能量，并且利用这些能量帮助它们生长！
Of course, evergreen trees also need lots of water, just like most other plants.
当然，和大多数植物一样，常青树也需要大量的水分。
But in many places, rain doesn't fall very often during the winter.
但在许多地方，冬天下雨的次数很少。
And trees can't use the water that's frozen into ice and snow.
并且树木不能吸收冰或雪状的水。
So a tree needs to hold on to the water inside it, for as long as it can.
所以树木必须得尽可能长时间的自己储水。
And the thin needles you find on evergreens help keep the water inside those trees,
常青树上的针叶能够帮助那些树木储水，
because they're covered with a thin layer of stuff that's kind of like wax.
因为它们外面覆盖了一层薄薄的，像蜡一样的东西。
This waxy layer helps trap water inside the needles, so the tree doesn't dry out.
这种蜡状层有助于锁住针叶里面的水分，所以树木不会干枯。
Another thing you might know about pine, spruce, and fir trees is that they make these neat little things called cones.
你可能了解到的关于松树、云杉和冷杉的另外一件事是，它们产生的平滑小果实叫做球果。
Cones can be big...or very small...and even colorful!
球果可大可小，甚至是五彩缤纷的！
A cone's job is to make the seeds that will someday grow into new trees!
球果的作用就是生产种子，这些种子有一天可能会成为一棵新的树木！
In fact, if you look deep inside a pine cone, you'll see the seeds inside.
事实上，如果你看到松果的深处，你会看见里面的种子。
These seeds are a tasty snack for animals like squirrels, chipmunks, and birds.
这些种子是松鼠，花栗鼠和鸟类等动物的美味小吃。
And evergreens that have cones also have a special name.
能产生球果的常青树也有一个特殊的名字。
This group of plants is called conifers.
这类植物叫做针叶树。
The name has the word "cone" right in it!
这个名字里面正好有个"cone"！
And pine, spruce, and fir aren't the only conifers out there!
松树，云杉和冷杉不是唯一的针叶树。
Some of the biggest conifers in the world are known as giant sequoia trees.
世界上最大的针叶树中数巨红杉最为著名。
Giant Sequoias live in the Western United States, and they live up to their name—
巨红杉生长在美国的西部地区，并且它们名至实归――
because they can grow to be enormous.
因为它们可以长成参天大树。
Many of these trees are wide enough to drive a car through.
许多这类树木足够宽，一辆汽车都能穿过。
One of these trees is almost eighty four meters tall, and about eleven meters wide.
有一颗树高达近84米，宽达约11米。
It even has a name: General Sherman.
它甚至有个名字，叫做雪曼将军树。
And scientists say that, while it's not the tallest tree in the world,
科学家说，尽管它不是世界上最高的树木，
it's the biggest, heaviest tree overall.
但它却是全世界最大，最重的树木。
Trees like General Sherman grow to be so big, because they live for a really long time.
像雪曼将军树这样的树之所以能长的如此高大，是因为它们活地很久。
Some sequoias can live for over three thousand years,
有些红杉可以存活三千年，
making them some of the oldest living things on the planet.
这使得它们成为地球上最古老的生物之一。
Now, you might see lots of pictures or drawings of conifers in cold and snowy places.
现在，你可能在寒冷有雪的地方看到过许多针叶树的照片或者绘画。
But they don't only grow where it's cold!
但是针叶树不止生长在寒冷的地方！
Some of the most common plants in hot, dry places are conifers, too—like the cedar and the cypress.
在炎热干燥的地方，一些最常见的植物就是针叶树，如雪松和柏树。
And many evergreens in these places have a different kind of leaf.
生长在这些地方的常青树它们的叶子也不一样。
Instead of being thin and pointy like a needle, cedar leaves are thin and flat.
雪松的叶子是薄而平滑的，并非像针叶树的叶子一样薄而尖。
This kind of leaf is called a scale, and they do seem a little like the thin and flat scales of a fish.
这种叶子被称为鳞片，它们看起来确实有点像鱼的扁平鳞片。
Just like needles, scales help the evergreen save water, so it can stay green even when it's very dry.
就像针叶一样，鳞片有助于常青树储存水分，所以即使天气干燥，树木也能保持常青。
Okay, let's talk about one more evergreen.
好了，让我们再谈谈另一种常青树。
This one is known for its broad, flat leaves and brightly colored berries.
这种树因它宽大扁平的叶子和五颜六色的浆果而著称。
Right you are, Squeaks! It's holly!
没错，Squeaks！它就是冬青树！
Holly is an evergreen with leaves that are often dark green and prickly around the edges.
冬青树是一种常青树，它的叶子通常是暗绿色的，叶子边缘布满了刺。
And just like needles, holly leaves have a shiny coating on them that helps them save water when it's dry.
并且就像针叶一样，冬青树的叶子上面有一层有光亮的涂层，当天气干燥时，这些涂层有助于储水。
Holly is not a conifer, so it doesn't make cones.
冬青树不是针叶树，所以它不会结球果。
Instead, the seeds of holly plants are found inside the berries.
相反的是，冬青植物的种子在浆果里面。
Although the most famous kinds of holly have red berries,
尽管最著名的冬青树结出的浆果是红色的，
some holly plants make berries that are white, orange, or even black.
但有一些冬青植物结出的浆果是白色的，橘色的，甚至是黑色的。
So even when it's wintertime, many kinds of trees keep their green!
所以即使冬天来了，有些植物还是绿色的！
Here's hoping you get outside and have a chance to see some of these excellent evergreens this winter!
这个冬天，我希望你能出去走走，看看那些出色的常青树！
Thanks for joining us on SciShow Kids!
感谢您收看儿童科学秀!
Do you have a question about something in the world around you?
你对周边的世界存有什么疑问吗？
If so, ask a grownup to help you leave a comment down below, or send us an e-mail to kids@scishow.com!
如果有，让大人帮你在下面留言，或者发邮件到kids@scishow.com!
Thanks! See ya next time.
谢谢观看！我们下次再见。
