You are twenty-one, a grown-up young lady old enough to make up your own mind.
你已经21岁了,已经到了可以自己做主的年龄了。
Your unit price seems fair enough, but we're hoping for a higher discount rate.
单价似乎合理,但我们希望给予更高的折扣率。
Libraries made education possible, and education in its turn added to libraries: the growth of knowledge followed a kind of compound interest law, which was greatly enhanced by the invention of printing.