四. 在科技文章中，数字频繁出现，用阿拉伯数字比用单词陈述更有利。

Eg. The new engine has a capacity of 4.3 litres and a power output of 153 kilowatts at 4400 revolutions per minute.

这台新发动机的容积为4.3升，转速为每分钟4400转，时输出功率是153千瓦。 来源：考试大

Eg. We know that the weight of a cubic foot of air at 0?C and 76cm，pressure is 0.08l pound, or 12 cubic feet of air weigh a pound.

我们知道，1立方英尺的空气在0摄氏度和760毫米汞柱压力下，重量是0.81磅，也就是说12立方英尺空气的重量是1磅。

五. 句首不用阿拉伯数字，句末要尽量避免用阿拉伯数字。

Eg. 4th July is an important date in American history. 来源：考试大

应该写成The fourth of July... 来源：考试大

Eg. 19 couples took part in the ballroom dancing competition.

19对选手参加了交际舞比赛。

应改写成：Nineteen couples took... 来源：考试大

Eg. 60％ profit was a reported．

据报道有60％的利润。来源：考试大

应改写成：Sixty per cent profit… 来源：考试大

Eg. 1345 kilograms force was applied at the center point of the bar.

试验时，在杆的中点加了1345公斤力。 来源：考试大

可改成When tested, a force of l345 kg was applied...

六. 遇到分数，可用带连字符的单词表示。

Eg. At 1east two-thirds of the class have had colds.

这个班至少有三分之二的学生患重感冒。来源：考试大

Eg. Nitrogen forms about four-fifths of the atmosphere.

氮约占大气的五分之四。