[填空题]Female koalas generally have a longer life span than males as they arc less frequently involved in fights.

[填空题]Female koalas generally have a longer life span than males as they arc less frequently involved in fights.

[单项选择]Some recent historians have argued that life in the British colonies in America from approximately 1763 to 1789 was marked by internal conflicts among colonists. Inheritors of some of the viewpoints of early twentieth century Progressive historians such as Beard and Becker, these recent historians have put forward arguments that deserve evaluation. The kind of conflict most emphasized by these historians is class conflict. Yet with the Revolutionary War dominating these years, how does one distinguish class conflict within that larger conflict Certainly not by the side a person supported. Although many of these historians have accepted the earlier assumption that Loyalists represented an upper class, new evidence indicates that Loyalists, like rebels, were drawn from all socioeconomic class. (It is nonetheless probably true that a larger percentage of the well-to do joined the Loyalists than joined the rebels.) Looking at the rebels side, we find little evidence for the contention tha
A. potentially verifiable
B. partially justified
C. logically contradictory
D. ingenious but flawed

[填空题]Longer span of work life, from the national policy perspective, eases ______.

[填空题]

The human species has increased its life span by ______.

[单项选择]Despite the fact that the life span of animals is conveniently divided into separate stages, including the prenatal, adolescent, and senescent, these periods are not truly______.
A. co-dependent
B. reflexive
C. distinct
D. coterminous
E. continuous

[单项选择]

Museums have changed. They are no longer places that one "should" go to but now they are places to enjoy.
At a science museum in Canada, you can feel your hair stand on end as harmless electricity passes through your body. At the Children’s Museum in New York, you can play an African drum. There are no "Do Not Touch" signs in some other museums in the USA.
More and more museum directors have realized that people learn best when they can become part of what they are seeing. In many science museums, the visitors are encouraged to touch, listen, operate and experiment so as to discover scientific rules for themselves.
The purpose is not only to provide fun, but also help people feel at home in the world of science. If people don’t understand science, they will be afraid of it; and if they are afraid of science, they will not make the best use of it.
One cause of all these changes is the increase in wealth and spare time
A. 3,500.
B. 2,000.
C. 3,000.
D. 6,000.