左腹股沟疝数月，反复脱出，平卧即消失，诊断为（） A.可复性疝 B.Littre疝

元素周期表是学习化学的重要工具。下列关于元素周期表的说法不正确的是

A．第七周期的最后一个元素为118号元素

B．元素周期表中第1、2纵行又称为s区

C．元素周期表中ⅠA是包含元素种类最多的纵行

D．根据元素周期表可以预测元素的存在及其性质

More than 6000 children were expelled(开除) from US schools last year for bringing guns and bombs to school, the US Department of Education said on May 8.

The department gave a report on the expulsions as saying handguns accounted for 58 percent of the 6093 expulsions in 1996—1997, against 7 percent for rifles(步枪) or shotguns and 35 percent for other types of firearms.

"The report is a clear sign that our nation’s public schools are cracking down(严惩)on students who bring guns to school", Education Secretary Richard Riey said in a statement, "We need to be tough-minded(坚强的) about keeping guns out of our schools and do everything to keep our children safe. "

In March 1997, an 11-year-old boy and a 13-year-old using handguns and rifles shot dead four children and a teacher at a school in Jonesboro, Arkansas. In October, two were killed and seven wounded in a shooting at a Mississippian school. Two months later, a 14-year-old boy killed three high school students and wounded five in Daducab, Kentucky.

"Most of the expulsions(开除), 56 percent, were from high schools, which have students from about age 13, 34 percent were from junior high schools and 9 percent were from elementary schools. " The report said.

From this passage we know that（）.

A．every American cannot have guns

B．only soldiers and the police can have guns

C．every American citizen can own guns

D．teachers have no money to buy guns

关于筛检试验的论述正确的是（）。

A.可以区别病人和非病人

B.受试对象是表面健康的人群

C.筛检的疾病应是当地的一个重大的公共卫生问题

D.筛检出来的疾病应具备有效的治疗与控制办法或措施

E.筛检出来的疾病应有进一步确诊的方法或条件

资本国际化的根本动因是( )。

A．资本无限增值的本性

B．推动世界经济的共同发展

C．争夺国外市场

D．生产国际化发展的要求

按照“先进先出”的原则组织数据的结构的是______。