实用法宝
3 ．Abacuses are so fast and accurate that people still use them today． 算盘计算很快并且很准确，因此人们至今仍在使用。
☆so…that引导的是结果状语从句，表示结果，意为―如此……以致‖。结果状语从句须里于主句之后。例：
The sound was so weak that nobody could hear it．声音如此小，没人能听见。
4 ．Use your own living computer to solve the problem above．用你自己的活电脑来解决上面的问题。
*a living computer一台活电脑。例：The brain is called a living computer．大脑被称作活电脑。
☆辫析：question，problem两者均可表示―问题‖o question多指对不懂的事情提出的问题，往往期待他人给予解答，常与answer连用；problem指客观存在的并有待解决的难题，常与solve连用。例：
She couldn't answer the question．她未能回答这个问题。
We have some problems to solve．我们有些问题需要解决。
5 ．If it is not powerftil enough，you will find the answer on page 59.如果它不够强大，你可以在59页找到答案。
☆if后为条件状语从句，表示―如果……‖，主句用一般将来时，从句要用一般现在时。例：
Will you come if he comes here? 如果他来，你会来吗？
6. "0‖的不同表达
zero/naught（nought) /nothing/nil
三 重点语段翻译
Numbers：Everyone's language
How many languages do you know? Everyone knows at least two-his or her own language and the international language of numbers．
Ancient numbers．
In ancient times，people wrote numbers in many different ways，as these pictures of the number
6 show．However, they nearly all counted in the same way-一一in tens． Zero
The system of numbers that nearly everyone uses today consists of the numbers from 1 to 9 and 0（zero)．With these ten numbers，we can write any number from the biggest to the smallest ．The Indians first invented and developed the 1 to 9 system of numbers ．They then invented the zero．This was a very important invention because it made it easier to write big numbers and to calculate．
Calculating machines
One of the first calculating machines was an abacus ．Abacuses are so fast and accurate that people still use them today ．On the abacus in the picture，the beads on the wires represent ones，tens，hundreds and thousands，starting from the bottom wire．
The picture on the right shows a modern electronic calculator. It can add，subtract，multiply and