患者男，50岁，缺失，以为基牙行可摘局部义齿修复制备支托凹的近远中径应为（） A.近

若a^k-2a^x=a，则x等于  [ ]

A.2-k

B.3-k

C.k-3

D.4-k

Whether we should allow marine (海洋的) parks to stay open has been widely debated in our community recently. A variety of different arguments have been put forward about it.

Smith, a sociologist, argued that dolphin parks provide the only opportunity for much of the public to see marine mammals.  As this argument goes, most Australians live in cities and never get to see these animals. Marine parks allow the average Australian to appreciate our marine wildlife. However, in fact, there are many places where they can be seen in the wild. Moreover, these places do not charge an overpriced entry fee — they are free.

Dr. Alison Lane, the director of the Cairns Marine Science Institute, insists that we need marine parks for scientific research. She argues that much of our knowledge of marine mammals comes from studies which were undertaken at marine parks. The knowledge which is obtained at marine parks can be useful for planning for the preservation of marine mammal species. However, Jones, a zoologist, explains that park research is only useful for understanding captive animals and is not useful for learning about animals in the wild. Their diets are different, they have significantly lower life lengths and they are more likely to have a disease. In addition, marine mammals in dolphin parks are trained and this means that their patterns of social behaviour are changed.

The Marine Park Owners Association holds that marine parks attract a lot of foreign tourists. This position goes on to state that these tourists spend a lot of money, increasing our foreign exchange earnings and assisting our national balance of payments. However, foreign tourists would still come to Australia if the parks were closed down. Indeed, surveys of overseas tourists show that they come here for a variety of other reasons and not to visit places like Seaworld. Tourists come here to see our native wildlife in its natural environment and not to see it in cages and concrete pools. They can see animals in those conditions in their own countries.

In a word, perhaps an agreement cannot be reached now. However, a question does deserve our consideration: If we continue with our past crimes against these creatures, how will our future generations view us?

小题1:Who support(s) the idea of closing marine parks?

A．Most Australians.

B．Alison Lane.

C．Smith.

D．Jones.小题2:What does the author intend to tell us in Paragraph 3 ?

A．The results from studies are valuable in animal preservation.

B．Scientific research at the marine parks has its limitations.

C．Captive animals have biology changes in marine parks.

D．Human behavior causes harmful effects on the animals.小题3:Which is NOT the reason to keep marine parks?

A．For entertainment purpose.

B．For scientific research purpose.

C．For economic purpose.

D．For political purpose.小题4:The author tries to persuade readers to accept his argument mainly by             .

A．pointing out the problems with keeping the marine parks

B．using evidence he has collected at the marine parks

C．discussing the advantages of animals' natural homes

D．questioning the way the animals are studied

控制项目目标的主要措施包括组织措施、管理措施、经济措施和技术措施，其中( )是最重要的措施。

A．组织措施
B．管理措施
C．经济措施
D．技术措施

正常输尿管有几个生理性狭窄（）

A.3个狭窄

B.2个狭窄

C.5个狭窄

D.4个狭窄

E.6个狭窄

A 5-liter jug contains 4 liters of a saltwater solution that is 15 percent salt. If 1.5 liters of the solution spills out of the jug, and the jug is then filled to capacity with water, approximately what percent of the resulting solution in the jug is salt ？（）

A.A

B.B

C.C

D.D

E.E