今天我来为大家介绍一下梧桐树。
梧桐树,即“中国梧桐”,是梧桐科梧桐属的植物,别名青桐、桐麻,也属落叶大乔木,一般高达15米;树干挺直,树皮绿色,平滑。原产中国,南北各省都有栽培,也为普通的行道树及庭园绿化观赏树。我们所说的法国梧桐其实是悬铃木中的一种。
梧桐树的叶子极似枫树叶,甚至连脉络都一样。梧桐树的叶子会变色哦!春天的时候,叶子是嫩绿嫩绿的;一到秋天,叶子就会慢慢变黄。这是为什么了呢?原来在夏天时,树叶工作得很努力,可是,天气转凉后,它就停止了工作。树叶所制造的营养也就不能送到树枝和树干上,而沉淀在叶子里。树叶的叶绿素也会遭破坏,就和留在叶子里的养分或枯萎了的茶褐色混合,这样就变成各种美丽的颜色了所有的树叶中都含有绿色的叶绿素,树木利用叶绿素捕获光能并且在叶子中其他物质的帮助下把光能以糖等化学物质的形式存储起来。除叶绿素外,很多树叶中还含有黄色、橙色以及红色等其他一些色素。虽然这些色素不能像叶绿素一样进行光合作用,但是其中有一些能够把捕获的光能传递给叶绿素。在春天和夏天,叶绿素在叶子中的含量比其他色素要丰富得多,所以叶子呈现出叶绿素的绿色,而看不出其他色素的颜色。当秋天到来时,白天缩短而夜晚延长,这使树木开始落叶。在落叶之前,树木不再像春天和夏天寻样制造大量的叶绿素,并且已有的色素,比如叶绿素,也会逐渐分解。这样,随着叶绿素含量的逐渐减少,其他色素的颜色就会在叶面上渐渐显现出来,于是树叶就呈现出黄、红等颜色。
梧桐树的价值也很大哟。梧桐树为栽培于庭园的.观赏树木。木材轻软,为制木匣和乐器的良材。种子炒熟可食用或榨油,油为不干性油。根皮、茎、叶、花、果和种子均可药用,治腹泻、疝气、须发早白,有清热解毒的功效。树皮的纤维洁白,可用以造纸和编绳等。木材刨片可浸出粘液,称刨花,润发。
梧桐子是梧桐树的种子。秋末至冬初采收,除去杂质,晒干。干燥种子,圆球形或类圆形,径6~8mm,黄棕色至深棕色,表面皱缩成网纹状。外层种皮较脆,易破裂,内层种皮坚韧。除去后,内有肥厚的淡黄色胚乳;子叶两片薄而大,紧贴在胚乳上,胚根位于较狭的一端。气、味均微。以个大、饱满、棕色、无杂质者为佳。陶隐居云:“桐树有四种,青桐叶皮青似梧而无子。梧桐色白,叶似青桐而有子,子肥亦可食。”李时珍说:“梧桐处处有之。树似桐而皮青不皵,其木无节直生,理细而性紧。叶似桐而稍小,光滑有尖。其花细蕊,坠下如醭。其荚长三寸许,五片合成,老则裂开如箕,谓之藁鄂。其子缀于藁鄂上,多者五六,少或二三。子大如胡椒,其皮皱。其子,甘平无毒。”
梧桐树就是这样的哟。
dear cathy,
i’m very glad to tell you something about china's second manned spacecraft shenzhou vi.
it was launched at 9 o’clock, oct 12, 20xx. and it returned to earth at about half past 4, oct 17. shenzhou vi orbited around the earth at a speed of 7.9 kilometers per second and traveled 3.25 million kilometers during the 115 hours and 33 minutes’ journey in space. the total cost is rmb900 million . aboard the craft were two astronauts, fei junlong and nie haisheng, who conducted a lot of scientific experiments. their journey in space was very smooth. the living and working conditions inside the cabin were very good. their health is in good condition.
ok, i have to stop here. looking forward to hearing from you soon!
yours,
li bo
现在社会进步得飞快,各式各样的钟表更是多得数不胜数,而在那么多钟表中,我还是最喜欢摆在我床头的那个小闹钟。
那个小闹钟的外形是个可爱的丁当猫,圆圆的脸像个大面饼,雪白雪白的。大大的脸上长着一对绿豆般大的眼睛,黑得透亮,和脸形成了鲜明的对比。在脸蛋的两旁,立着两只小巧玲珑的耳朵,看它的神情好像在认真地听着主人的述说。最漂亮的还要数它耳朵上的那个粉红色蝴蝶结。你可不要小看了这个蝴蝶结,它可不是单单用来装饰的。只要按一下这个蝴蝶结,这个丁当猫就会亮起来,像一盏小灯,每天晚上我都会和它说悄悄话,所以它也是我的“知心朋友”。这个丁当猫的下半身就是一个可爱的小闹钟,所以它最大的特点就是上身大下身小。
其实,我以前也不怎么喜欢这个小闹钟,总觉得它太普通了,并没有给我多大的帮助。我对这个小闹钟的看法是在一个星期一的早晨才改变的。那天早晨,我正在香甜的睡梦当中,突然响起了一阵急促的铃声,我心想:“大清早,乱叫什么,扰了我的好梦。”我把闹钟拿到眼前,瞟了一眼。“呀!”真是不看不知道,一看吓一跳,已经是七点十分了。我从床上跳起来,抓起衣服就往身上穿。穿完衣服,挎上书包,就往外冲。一直冲到班门口,上课铃准时打响了。多亏了这个小闹钟,要不然,我还在被窝里呼呼大睡呢!
从此以后,我就把这个小闹钟放在我的枕头边上,和它聊天。它也用清脆的滴答声回应我。
我喜欢这个可爱的丁当猫小闹钟。
瓷器是中国的特产,有的瑰丽;有的朴素;有的简约。但都透露出一股中国风。
从夏商周的灰陶、黑陶、红陶、彩陶、白陶、带釉硬陶开始,瓷器就是人们生活中不可缺少的一部分。这仅仅是瓷器发展的开始,到了隋朝时期,瓷器中的青瓷开始烧造,白瓷得到了很好的发展。而当历史的转轮,转向唐朝时,真正的瓷器出现了。这是陶与瓷的分水岭,因为在此之前的陶瓷质地脆弱,只能算作原瓷。
越窑和邢窑也是此时期出现的,在五代十国时期时期,越窑成为吴越王钱氏的御用器皿。并且在此阶段中,天青色出现,获得了「雨过天晴青」的美称。
到了宋朝,定窑、汝窑、官窑、哥窑、钧窑,形制优美,高雅凝重。其程度前无古人,后无来者。
明清两朝,瓷器更是花样百出,万历年间有名的五彩、斗彩、成为后世彩瓷发展的基础,甚至日本伊万里古瓷也是根据这时期的斗彩发展出来,「万历彩」也就在史上成名。同时又有红地黄彩、蓝地黄花、红地青花、黄地青花五彩、描红等等各式彩瓷。
但无论瓷器如何变化,他都是中华民族的一份骄傲!
Dearest Mother and Father:
I thank you for all the things you did for me over these years, without you, I would still be a toddler that don't know how to respect my friends. Without you, I would remain a child forever, without you, my homeworks and assignments would forever be "lost" and excused. I remembered, clear as glass, the glorious days we had when I was young, when we went travelling everywhere and our smiles on our pretty faces each and every single second. My heart felt very warm and thankful whenever I thought of you, it's like there's an unknown bond between the three of us, it tied us together, and made us a true family.
Your Love and Star,
xx
Dear Frank,
How is everything going? I have been in America for a month as an exchange student. I am now staying at Mrs. White’s. She is said to be in her forties but looks very young and attractive. She is of normal height, with a slender figure, blond hair and big blue eyes.
Mrs. White shows a keen interest in everything about China, especially its culture and places of interest. She has a large collection of items that have to do with China, such as books videos, tea, artworks, and so on. She asks me so many questions about my country that sometimes I have to consult my friends to give satisfactory answers.
Mrs. White is kind and outgoing and she usually wears a smile on her face. We are getting along very well with each other. She takes me out to local places every weekend and if you come here, I will be your guide.
Look forward to your reply.
Yours,
Li Hua
“You always say that I am naive. In your eyes, I am always the little girl who will never grow up”. This is my favorite song and also the sound from the bottom of my heart. You made me feel so lucky to be your child. But I find our hearts getting further apart as time goes by.
You strictly forbid me to do entertaining activities even if I finished my homework, such as watching TV or playing computer games. Based on this, I couldn’t get any grade less than A. It is said that genius only means hard-working all one’s life. But I think combining exertion is the best way for learning.
The most important thing to me was that I feel frustrated for having few friends to confide in due to your strict rules. I can’t have a play date, participate in a school play or even choose my own extracurricular activities. Who will accept such a boring and troublesome person? I am just an ordinary girl who can’t stand loneliness, so I always feel contradictory.
On the one hand, I’m grateful to have you in my life, to disappoint you was the least I would do. On the other hand, what you asked for me made me felt like a puppet rather than a real person. I appreciated your efforts to pull me away from a self-indulgent life, but your obsessively extravagant strictness has pushed me into an isolated and insensible one. I need a little freedom so that I will concentrate on something I really interested in.
Father and mother, these words were hid in my deep heart for a long time. I love you, and I believe if you change some harsh rules. I will have a wonderful life.
Best wishes.
Yours, daughter
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