英語倍數的表達規律
英語裡表示倍數增減的方式很多，比較常用的有以下幾種。
1.用"倍數 +as + 副詞（形容詞） + as"句型表示。翻譯這類句子時，可設句子中的倍數為X， 含有增加意義的句子可譯成"A是B的X倍"或"A比B高、快、多、大 X-1倍； 含有減少意義的句子可譯成"A是B的1/X"。例如：
This room is twice as big as that one.
這間房子是那間房的2 倍大。/這間房比那間房大一倍。
You run twice as slow as I.
你跑的速度是我的1/2.
This box is three times as heavy as that one.
這個箱子有那個箱子的3倍重。
2.用"as + 副詞（形容詞）+as + 數字"句型表示。在這類句型中，含有增加意義的句子看可按"高（多、長）達 + 句中數字"的方法譯出，含有減少意義的句子可按"低（少、短）達 + 句中數字"的方法進行翻譯。
The mountain is as high as 7000m.
這座山高達7000米。
The area of the smallest country in the world is as small as 0.44 square kilometers.
世界上最小國家的面積小至0.44平方公里。
3.用"倍數 + the size (length, height等) of "表示。用法與句型1相似。
Shanghai is about four times the size of Changsha. (= Shanghai is about four times as large as Changsha.)
上海大約有長沙的4倍那樣大。
In this workshop the output of July was 3.5 times that of January. (= In this workshop the output of July was 3.5 times as much as that January.)
這個車間7月份的產量是一月份的3.5倍。
4.用"倍數 + 比較級 + than"句型表示，表示"增加了（減少了） + 句中數字"。
This reservoir is three times larger than that one.
這個水庫比那個水庫大3倍。
The sun is a million times larger than the earth.
太陽比地球大100萬倍。
5."increase (decrease, reduce ) + by + 數字（倍數）"。這種句型，可按by 後表示的淨增減的數或倍譯出。
The prime cost decreased by 60%.
主要成本降低了60%。
Compared with last year, our coal output has increased by three times.
與去年相比，我們的煤產量增長了3倍。
6. "increase (decrease, reduce ) + to + 倍數" 為增或降至X倍。
The number of the students has increased to three times.
學生人數增加到3倍。
The price of rice has reduces to two thirds.
大米的價格降到原價的2/3.
7."倍數+ upon (over)",意為 "超過X倍"。
The industrial output in our factory this year is ten times over that of 2001.
今年我們工廠的產量比2001年增加了10倍。
He is three times upon your age.
他的年齡是你的4倍。
8. "exceed (increase, decrease, reduce ) + by a factor of + 倍數"可譯為"增加了x-1倍"或"減少至原來的1/X".
This speed exceeded the average speed by a factor of 2.5.
該速度超過平均速度的1.5倍。
This equipment will reduce the error probability by a factor of 5.
這種設備使誤差率降到原來的1/5.
9."倍數 + what -從句"表示"為……的……倍" 。
They turned out 400 kinds of products with a total value more than 42 times what it was in 2010.
他們生產了400種產品，總產值為2010年的42倍多。
在使用上述句型時，還應注意以下幾點：
1） 在表示"2倍"時，不能用two times. 除twice 外，還可用double, as…again as 等。
He demanded double the usual fate.
他要了比平常多1倍的路費。
A is as long again as B.
A 的長度是B的2倍。
2） 在表示"3 倍"時，除可用three times外，還可用動詞treble 或triple等表示。
The grains in the area have trebled this year.
今年這個地區的糧食增加了2倍。
In agriculture, the number of farms in the United States tripled between 1960 and 1910.
在農業方面，1910年美國的農場數目是1960年的3倍。
3） 在表示"4倍"時，或4倍以上時，除用"基數詞 + time"外，還可用"基數詞 +fold"的合成詞。
We have produced four-fold as many electric fans as we did last year.
本年我們生產的電扇數量相當於去年的4倍。
During that period its total output of industry increased (to) ten-fold.
在那個時期，工業總產值增加了9倍。
4） 在表示"不到1倍"時，還可用"分數+as…again as "表示。
A is half as much again as B.
A比B多一半。
A is two-thirds as heavy again as B.
A比B重2/3.
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