挖掘机上的安全锁定操纵杆作用是什么？

对放在道床肩上或道心的长钢轨应派人巡检。

空气洁净度所要控制的对象是( )。

A．空气中最大控制微粒直径

B．空气中的微粒数量

C．空气中最小控制微粒直径和微粒数量

D．空气中最小控制微粒直径

股票具有的特征包括（）。

A.风险性

B.永久性

C.流动性

D.参与性

For more than a decade, the prevailing view of innovation has been that little guys had the edge. Innovation bubbled up from the bottom, from upstarts and insurgents. Big companies didn’t innovate, and government got in the way. In the dominant innovation narrative, venture-backed start-up companies were cast as the nimble winners and large corporations as the sluggish losers.

There was a rich vein of business-school research supporting the notion that innovation comes most naturally from small-scale outsiders. That was the headline point that a generation of business people, venture investors and policy makers took away from Clayton M. Christensen’s 1997 classic, The Innovator’s Dilemma, which examined the process of disruptive change.

But a shift in thinking is under way, driven by altered circumstances. In the United States and abroad, the biggest economic and social challenges—and potential business opportunities—are problems in multifaceted fields like the environment, energy and health care that rely on complex systems.

Solutions won’t come from the next new gadget or clever software, though such innovations will help. Instead, they must plug into a larger network of change shaped by economics, regulation and policy. Progress, experts say, will depend on people in a wide range of disciplines, and collaboration across the public and private sectors.

"These days, more than ever, size matters in the innovation game," said John Kao, a former professor at the Harvard business school and an innovation consultant to governments and corporations. In its economic recovery package, the Obama administration is financing programs to generate innovation with technology in health care and energy. The government will spend billions to accelerate the adoption of electronic patient records to help improve care and curb costs, and billions more to spur the installation of so-called smart grids that use sensors and computerized meters to reduce electricity consumption.

In other developed nations, where energy costs are higher than in the United States, government and corporate projects to cut fuel use and reduce carbon emissions are further along. But the Obama administration is pushing environmental and energy conservation policy more in the direction of Europe and Japan. The change will bolster demand for more efficient and more environmentally friendly systems for managing commuter traffic, food distribution, electric grids and waterways.

These systems are animated by inexpensive sensors and ever-increasing computing power but also require the skills to analyze, model and optimize complex networks, factoring in things as diverse as weather patterns and human behavior. Big companies like General Electric and IBM that employ scientists in many disciplines typically have the skills and scale to tackle such projects.

In his book Christensen comes to the conclusion that（）

A. business people are more innovative than government officials

B. all kinds of changes are disruptive activities in some sense

C. the dilemma of any innovation is its disruptive nature

D. small businesses are more creative than large companies

JavaScript中的对象由（）和（）两个基本元素构成。