问题 单项选择题 A1/A2型题

女性,40岁。行直肠癌根治术(Miles手术)后第3天出现右侧腰部疼痛。B超检查:右肾轻度积水。根据患者情况,首先要进行的检查是()。

A.双肾CT

B.静脉肾盂造影或逆行肾盂造影

C.全腹CT

D.腹部X线平片

E.B超

答案

参考答案:B

解析:直肠癌根治术(Miles手术)易损伤输尿管,术后怀疑发生输尿管损伤时,备选答案中A、CD、E选项均不能提供全面的诊断信息。静脉肾盂造影或逆行肾盂造影则可了解肾脏的功能或形态,关发现输尿管狭窄、尿外渗等情况,因此选B。

单项选择题 A1型题
单项选择题 案例分析题

Questions 21 to 25 are based on the following passage.

Lead deposits, which accumulated in soil and snow during the 1960’s and 70’s, were primarily the result of leaded gasoline emissions originating in the United States. In the twenty years that the Clean Air Act has mandated unleaded gas use in the United States, the lead accumulation worldwide has decreased significantly.

A study published recently in the journal Nature shows that air-borne leaded gas emissions from the United States were the leading contributor to the high concentration of lead in the snow in Greenland. The new study is a result of the continued research led by Dr. Charles Boutron, an expert on the impact of heavy metals on the environment at the National Center for Scientific Research in France. A study by Dr. Boutron published in 1991 showed that lead levels in arctic (北极的) snow were declining.

In his new study, Dr. Boutron found the ratios of the different forms of lead in the leaded gasoline used in the United States were different from the ratios of European, Asian and Canadian gasolines and thus enabled scientists to differentiate (区分) the lead sources. The dominant lead ratio found in Greenland snow matched that found in gasoline from the United States.

In a study published in the journal Ambio, scientists found that lead levels in soil in the Northeastern United States had decreased markedly since the introduction of unleaded gasoline.

Many scientists had believed that the lead would stay in soil and snow for a longer period.

The authors of the Ambio study examined samples of the upper layers of soil taken from the same sites of 30 forest floors in New England, New York and Pennsylvania in 1980 and in 1990. The forest environment processed and redistributed the lead faster than the scientists had expected.

Scientists say both studies demonstrate that certain parts of the ecosystem (生态系统) respond rapidly to reductions in atmospheric pollution, but that these findings should not be used as a license to pollute.

The authors of the Ambio study have found that()

A.forests get rid of lead pollution faster than expected

B.lead accumulations in forests are more difficult to deal with

C.lead deposits are widely distributed in the forests of the US

D.the upper layers of soil in forests are easily polluted by lead emissions