振荡器和RC振荡器的工作原理基本相同,但LC振荡器产生的频率()。A.J较低 B.较

题型:单项选择题

问题:

振荡器和RC振荡器的工作原理基本相同,但LC振荡器产生的频率()。

A.J较低

B.较高

C.极低

D.时高时低

考点:仪表工考试热工仪表检修工(高级)热工仪表检修工(高级)题库
题型:单项选择题
解方程组:
x2+y2-2x-4y=0
2x-y-4=0
题型:单项选择题

下列哪项不属于干金温脾汤的组成()

A.附子

B.人参

C.大黄

D.芒硝

E.甘草、干姜

题型:单项选择题

Ashok Gadgil has spent the past three decades helping people in need—and he has no plans to stop .On May 2, Gadgil won the$100.000 Lemelson-MIT Award for Global Innovation. Each year,the honor is given to an inventor who has improved the lives of people in developing countries. Gadgil‘s inventions have helped more than 100 million people around the world.

Gadgil is a professor and physicist at the University of California. When he’s not teaching,he works to find solutions to global problems such as energy efficiency and water safety. “I chose to focus on problems where my knowledge of science could help,”he said

In the 1980s he came up with a program to make energy-efficient light bulbs more affordable for people in developing countries. Then in the 1990s,Gadgil designed his first life—saving invention,UV Waterworks .The device kills deadly disease —carrying germs(病菌)from drinking water. It costs just one cent to clean five liters of water .Gadgil was inspired to find an inexpensive solution to the clean water crisis after more than 10,000 people in his home country of India died from an outbreak of Bengal cholera,in 1993 The disease is spread through contaminated food and drinking water .So far,the invention has provided safe drinking water to more than five million people in poor areas.

As a professor,Gadgil encourages his students to stay positive about finding solutions to hard problems.“Be optimistic when you try a hard problem.”he says. “It’s when you solve a large problem that you can have a big impact on the world”

小题1:Gadgil was given Lemelson-MIT Award for___________.

A.his teaching experience

B.his new physical research

C.his vast knowledge

D.his helpful inventions小题2:What call we learn about UV Waterworks?

A.It's Gadgil’s first invention

B.It’s used to clean water.

C.it was designed for his home country

D.It saved 10,000 people in total小题3:The underlined word “contamninated”in Paragraph 3 means__________.

A.wasted

B.consumed

C.polluted

D.canned小题4:According to the last paragraph,Gadgil encourages his students__________.

A.to learn lessons from failures

B.to find problems in peaceful life

C.to make inventions to help poor people

D.to be confident when facing difficulties小题5:Which of the following can best describe Gadgil?

A.Caring and optimistic.

B.Independent and positive.

C.Powerful and strict.

D.Responsible and sensitive.

题型:单项选择题

慢性Ⅱ型呼吸衰竭最重要的诊断依据是()

A.发绀、呼吸困难

B.出现精神神经症状

C.二氧化碳结合力升高

D.PaO2<60mmHg,PaCO2>50mmHg

E.通气功能明显障碍

题型:单项选择题

在岩土工程分析评价中,下列( )项可仅作定性分析。

A.场地的稳定性与适宜性

B.各种临界状态的判定问题

C.土体的变形性状

D.岩土体的抗剪强度

更多题库