Blogger Ads

TOEFL福考試閱讀背景知識(二十二)

美國為什麼遷都華盛頓

1789年,美國聯邦政府正式成立,華盛頓當選為首任總統。當國會在紐約召開第一次會議時,建都選址問題引起激烈爭吵,南北兩方的議員都想把首都設在本方境內。國會最後達成妥協,由總統華盛頓選定南北方的天然分界線——波托馬克河畔作為首都地址,並聘請參加過獨立戰爭的法國工程師皮埃爾朗方主持首都的總體規劃和設計。
 
1799
年,華盛頓總統與世長辭,為了表示對華盛頓總統的敬意,國會決定以他的名字為首都命名。由於入選地域地跨馬裡蘭和維吉尼亞兩州,於是國會請馬裡蘭州再讓地178平方公里,維吉尼亞州讓地31平方公里,組成華盛頓哥倫比亞特區
 
1800
年,美國首都從費城遷到華盛頓。華盛頓市區的佈局以國會大廈為軸心,向西北、東北、西南、東南四個方向展開。街道的設計獨具匠心,南北向的街道按阿拉伯字母的順序排列,共22條街;東西向的街道按英文字母順序排列,也有22條街。在東西向和南北向街道之間,穿插著一些以州的名字或以政治詞彙命名的街道,這些街道分別呈東南一西北走向和東北一西南走向。街道交匯處和十字街口,形成了許多圓形小廣場,廣場全部被綠蔭花草覆蓋,廣場內有歷史人物銅像和噴泉。
 

Why is America’s capital in Washington, D.C.?

 

Why is the capital of the United States in Washington, D.C.?

Several cites have been the capital in several states, including New York, Philadelphia, Annapolis and Princeton.

George Washington wasn’t even president when the capital moved to Washingon, so the decision had nothing to do with him.

So why did the capital end up in Washington? Here are some possible reasons: geography, transportation, access to water, economics, politics, the weather, cost – or maybe they held a contest!

Does it make sense to have the capital so far from California, when more people live in California than any other state?

Critical thinking challenge: Why is America’s capital in Washington, D.C.?

    

關於鐘乳石的形成
石灰岩洞中的鐘乳石、石筍是怎樣形成的
  桂林是世界聞名的風景區,山奇水秀,風景美麗,因此自古就有桂林山水甲天下之稱。桂林除山水美之外,還有更具特色的石灰岩洞,七星岩是比較有代表性的溶洞。洞內到處懸垂著美麗的鐘乳石,有的像累累的果實,有的像盛開的花朵。與之相對應的石筍拔地而起,一個個像春天從地面下出來的竹筍。
  那麼這些奇麗的鐘乳石和石筍是怎樣形成的呢?
  原來盛產鐘乳石和石筍的溶洞都是石灰岩構成的。洞頂有很多的裂隙,每一處裂隙裡都有水滴滲透出來。每當水分蒸發掉後,那裡就會留下一些石灰質的沉澱,日積月累,天長日久洞頂上的石灰質愈積愈多,終於形成了乳頭。以後,乳頭外面又包起一層石灰質,以至越垂越長,就形成了姿態萬千的鐘乳石。
  石筍其實就是鐘乳石的孿生兄弟。當洞頂上的水滴落下來時,石灰質也在地面上沉積起來,就這樣石筍對著鐘乳石向上長起來,若是說鐘乳石是兄長,那石筍就是孿生弟弟了。
  而石筍底盤大,本身比較穩定不易折斷,所以它比鐘乳石的生長速度還要快,還要粗壯呢。

   

 

What's the difference between stalactites and stalagmites?

by 

 
 

Educational signs in the Luray Caverns in Virginia promote public understanding of the difference between stalactites and stalagmites.

Alan Band/Fox Photos/Getty Images

The Formation of Stalactites and Stalagmites

We can trace the words stalactite and stalagmite back to the Greek word "stalassein," which means "to drip." This is fitting because it describes how both are formed in nature. Although they look lifelike and a little creepy, stalactites and stalagmites grow simply because of water running over and through inorganic material.

Limestone caves, where most stalactites and stalagmites are found, are mainly composed of calcite, a common mineral found in sedimentary rocks. Calcite molecules are made of calcium and carbonate ions, and are referred to as CaCO3, or calcium carbonate. When rainwater falls over a cave and trickles through rocks, it picks up carbon dioxide and minerals from limestone. If we add water, carbon dioxide and calcium carbonate together, we get this equation:

H20 + CO2 + CaCO3 = Ca (HCO3)2

Ca (HCO3)2 is known as calcium bicarbonate, and the water carries the substance, basically dissolved calcite, through the cracks of the roof of a cave. Once water comes into contact with the air inside the cave, however, some of the calcium bicarbonate is transformed back into calcium carbonate, and calcite starts to form around the crack. As water continues to drip, the length and thickness of the calcite grows, and eventually a stalactite forms on the ceiling. It can take a very long time for most stalactites to form -- they usually grow anywhere between a quarter-inch and an inch every century.

Dorling Kindersley/Getty Images

It doesn't end there -- we haven't talked about stalagmites yet. Of course, stalagmites don't just emerge from the ground. The water dripping from the end of a stalactite falls to the floor of a cave and deposits more calcite into a mound. Soon enough, a stalagmite will form in a conelike shape. This is why you usually find stalactites and stalagmites in pairs, and sometimes they'll even grow together to form one big column. There are many limestone caves around the world famous for their displays of dripstone, including Carlsbad Caverns in New Mexico, Timpanogos Caves in Utah, Mammoth Cave in Kentucky and Jenolan Caves and Buchan Caves in Australia.

And if you ever forget which one's which, there are several classic memory tricks to get stalactites and stalagmites straight. Here are a few:

  • Stalactites have to hold on "tight" to the top of the cave
  • Stalactites hang from the ceiling like ladies' tights
  • Stalactite has a "t" in it, as in "t" for "top"
  • Stalactite has a "c" in it, as in "c" for "ceiling," and stalagmite has a "g" in it, as in "g" for "ground"

For lots more information on caves and all things speleological, see the next page.

 

 

 

創作者介紹
創作者 evita6804 的頭像
evita6804

愛薇塔樂學英文

evita6804 發表在 痞客邦 留言(0) 人氣()


留言列表

發表留言

您尚未登入,將以訪客身份留言。亦可以上方服務帳號登入留言

請輸入暱稱 ( 最多顯示 6 個中文字元 )

請輸入標題 ( 最多顯示 9 個中文字元 )

請輸入內容 ( 最多 140 個中文字元 )

請輸入左方認證碼:

看不懂,換張圖

請輸入驗證碼