640的英文是：six hundred and forty；
hundred：num.一百;许多;大量;100到999间的数目;百位数。
forty：n.四十;四十几。
相关介绍
After forty years in the police force nothing much shocks me
在警队呆了40年后，我对什么都见怪不怪了。
I was forty, the age when people take stock and change their lives.
我已年届不惑，到了该全面审视自己并改变生活的年龄了。
Two-way trade between the two countries increased by more than forty per cent last year
去年，两国间的双向贸易增长了40%多。
Now I can look back on the whole tragedy from a distance of forty years.
时隔40年后，现在我可以回顾整个悲剧了。
Forty per cent of the population is suffering from malnutrition
人口中有40%的人营养不良。
