食管内金属异物的X线检查方法是A．硫酸钡造影法 B．钡棉造影法 C．胸部断层像 D．

施工总承包企业的资质总共设立()个等级。

A.2

B.3

C.4

D.5

下列相关说法用分子的知识解释正确的是

A．A

B．B

C．C

D．D

患者，女性，70岁，因冠心病间断发生左心衰竭3年，半天来与家人争吵后心悸、气短、不能平卧，咳粉红色泡沫痰，急诊入院。体检：BP90／60mmHg，R28次／分，神清，坐位，口唇紫绀，心率130次／分，律齐，两肺满布湿啰音及哮鸣音。

急诊护士应给予患者的吸氧方式为（）。

A.持续低流量给氧

B.间断低流量给氧

C.低流量酒精湿化给氧

D.高流量给氧

E.高流量酒精湿化给氧

In the world of climate change, it is in the Earth’s cold regions where trends can most easily be seen. The cryosphere, where water is found in solid form, is among the most sensitive regions to temperature change.

The sensitivity of ice and snow to temperature changes is an early indicator of even relatively small differences, says University of Colorado at Boulder senior researcher Richard Armp. He has found that today’s receding and thinning sea ice, mountain glacier mass losses, decreasing snow extent, melting permafrost (永久冻土), and rising sea level are all consistent with warming.

Global mean temperatures have risen one degree Fahrenheit over the past 100 years. with more than half of the increase occurring in the last 25 years, observes Armp who is affiliated with the National Snow and Ice Data Center headquartered at CU-Boulder.

"As slight as that may seem, it’s enough to make a difference, " said Armp. "Now, long-term monitoring of a series of cold region, or cryospheric, parameters (参数) shows that for several decades the amounts of snow and ice around the world have been decreasing. "

The extent of Arctic sea ice is shrinking by about 3 percent per decade. but the trends are not uniform. While recent studies have indicated that the ice thickness also had decreased over several decades, new information shows that the ice may have thinned rapidly, Armp said. Examination of springtime ice thickness in the Arctic Ocean indicates that the mean ice thickness decreased 1.5 meters (4.8 feet) between the mid-1980s and early 1990s.

To mark its 25^th anniversary, the National Snow and Ice Data Center has organized a special session at the 2001 Fall Meeting of American Geophysical Union, taking place this week in San Francisco, that illuminates overall changes in the cryosphere.

The session begins Tuesday and extends through Thursday afternoon, with 75 contributions from all areas of cryospheric study. Papers and posters include examinations of lake and river ice, glacier dynamics, and mass ice balance studies in polar and continental glaciers, regional and polar snow cover trends, and variations in Canadian ice cap elevations.

The special session of the National Snow and Ice Data Center was organized to （）。

A. attract more contributions to the cryospheric regions

B. make more people realize the threats of climate change

C. stimulate further research into the changes in ice thickness

D. celebrate its 25^th anniversary and discuss changes in the cryosphere

我国《物权法》规定，当事人签订买卖房屋或者其他不动产物权的协议，为保障将来实现物权，按照约定可以向登记机构申请预告登记。预告登记后，债权消灭或者自能够进行不动产登记之日起（）个月内未申请登记的，预告登记失效。

A.1

B.2

C.3

D.4