单项选择题
As is known to all, trade and specialization go hand in hand and enable each of us to have more products to use（）
A．众所周知，现代贸易需要生产的专门化，才能让我们用到更多新产品。 B．众所周知，贸易和专门化相辅相成，使我们每个人能使用更多的产品。 C．众所周知，贸易和专门化总是同时进行，使我们能生产出更多的产品。 D．众所周知，现代贸易需要生产的专门化，才能够制造出更多的新产品。
单项选择题 We will offer you a 20 percent discount if you are among the first fifteen customers of the day（）
单项选择题 If we（）more time and money, we could have visited many more places.
单项选择题 Generally, it takes courage for an aged person（）a new life in a strange country.
