产品焊接试板为何要求进行无损检测（） A.保证试板焊接接头与产品焊接接头质量相当；

三位同学合作学习，对问题“已知不等式xy≤ax²+2y²对于x∈[1，2]，y∈[2，3]恒成立，求a的取值范围”提出了各自的解题思路．

甲说：“可视x为变量，y为常量来分析”．

乙说：“不等式两边同除以x²，再作分析”．

丙说：“把字母a单独放在一边，再作分析”．

参考上述思路，或自已的其它解法，可求出实数a的取值范围是（    ）．

补全对话。

A: Today we are going to talk about a great invention. It looks like a human being.   1    

B: It's a robot.    2    

A: Of course not. The first robot was invented in 1921.

B:    3    

A: Sure. They can take the place of humans to do some boring work. They can also do a lot of dangerous

work instead of humans.

B:    4    

A: No. Robots can do a lot of work instead of people in many ways, but people wouldn't be replaced by

robots.    5    

B: We get it.

A. Is that clear?

B. Can it do some washing?

C. Why do you think it is useful?

D. It appeared several centuries ago, didn't it?

E. Will robots be the same as people?

F. What is it?

G. Could you please tell me more about robots?

诺兰阶段模型把信息系统的成长过程划分为初装、蔓延、控制、（）、（）和（）等六个阶段。

A.计划、规划、处理

B.协调、成熟、终结

C.集成、数据管理、成熟

D.拓展、扩散、终结

今年为“世界物理年”，南京市某中学举行“让物理照亮世界”为主题的知识竞赛活动，其中有如下一个问题，请你解答．

日常生活中，我们看到小朋友用吸管水平吹出的肥皂泡，常常开始时上升，随后便下降．这是为什么？

患者，男，29岁，骨蒸潮热，盗汗遗精，足膝痛热，咳嗽咯血，心烦易怒，舌红少苔，脉数而有力，宜首选（）

A.生地

B.玄参

C.赤芍

D.紫草

E.知母