[单项选择]The U.S was in 1850 a (divided) nation half slave and half free.
A. allied
B. combined
C. united
D. separate

[单项选择]The U.S was in 1850 a divided nation half slave and half free.
A. allied
B. combined
C. united
D. separate

[单项选择]The U.S was in 1850 a (divided) nation half slave and half free.
A. allied
B. combined
C. united
D. separate

[填空题]Most people are half optimists and half pessimists.

[简答题]

Is the glass half-full or half-emptyDepends whether you’re an optimist or a pessimist.
But those two words are more than casual labels:research has established that(91) optimists have a consistent and upbeat way of dealing with adversity and that they are more successful in work,health and life in general than pessimists.
Optimists bounce back from trying times,generally with good grace,and see failure as a stepping-stone to success.Any problem tends to be minimised and dealt with later while the rest of life goes on as usual.
(92)Their upbeat approach,resilience and perseverance makes them ideal for jobs in high-pressure areas where setbacks are part of the territory:sales,brokering,public relations,presenting,creative jobs and high burn-out posts.They are often a company's visionaries.
Pessimists,however,risk unravelling and sinking into depression when one thread of their life breaks.They are less likely to cope well with

[填空题]Anthropologists have divided prehistoric North America Indian societies into three categories: bands, tribes, and chiefdoms. Bands were the earliest and most common form of social organization. However, it is unlikely that the first people who came to North America about forty thousand years ago traveled in bands. The climate in the Bering Strait region was so severe and food was so scarce that large groups of people, such as the bands, would have had great difficulty in making such a journey successfully. The earliest people probably traveled in single family units. Some of the units, however, may have gathered together periodically for social reasons.
(66)
Whatever the beginning of the bands in the New World, this form of organization was very common after the initial settlement of the continent. Bands flourished throughout North America until the time of European colonization. In many areas, they survived long after the arrival of the Europeans. When English