考查感叹句。英语感叹句由what和how引导,what后面跟名词,how后面跟形容词或副词。具体构成如下:(1)what + a/an+形容词+可数名词单数+主语+谓语!(2)what +形容词+不可数名词或可数名词复数+主语+谓语!(3)how+形容词或副词+主语+谓语!本句的中心词helpful是形容词,可知用how引导此感叹句;故选B。反馈...
Environmental impact:Nearly 75 percent of global carbon emissions come from the production and consumption of energy. This is because most electrical energy is generated by burning fossil-based fuels. At 460 terawatt-hours of annual electricity consumption, data centers comprise only a small fraction ...
electricity gridenergy storageelectric transportationbatteriessmart gridScientific American is the world's premier magazine of scientific discovery and technological innovation for the general public. Readers turn to it for a deep understanding of how science and technology can influence human affairs and ...
Wind power is energy, such as electricity, that is generated directly from the wind. It is considered a renewable energy source because there is always wind on the Earth and we aren't 1 the wind when we make energy from it. Wind power also does not cause pollution. ...
An electric field in a circuit is like an electron pump: a large source of negative charges that can propel electrons, which will flow through the circuit towards the positive lump of charges. Electric Potential (Energy) When we harness electricity to power our circuits, gizmos, and gadgets,...
1. What is Energy?energyformsourcesparticles in motionthermodynamicsEinstein's Equation: E = mc2Primary Energy Resources Oil Sands or Tar Sands? Oil Sands and Their Environmental Impact Water Usage Natural Gas Usage Greenhouse Gases Coal in Canada Natural Gas Nuclear Energy and Electricity Electricity...
Introduction to electricity What makes the lights in your room turn on and stay lit? Why does the flashlight come on when you press that switch button? They happen because there is energy flow in the form of electrical energy. Electrical energy exists and can be experienced in many ways and...
ElectricityElectricity is a kind of energy. It gives us power andflows through wires. We use electricity in hundreds ofways every day. We use it to watch TV,play computergames,see a film and read books at night. Fridges,washing machines and rice cookers can't work withoutelectricity. Electr...
用方框中所给的选项补全短文Electricity(电) is a form of energy and this is what powers the TV, hairdryer, mobile phone, fridge,electric toothbrush and more! Our growing need for energy is one of the problems facing the world today,51.Here are some simple ways to make a big difference ...
What is energy deregulation? To truly understand the potential of a deregulated energy market, you need to understand the history of energy in the U.S. Energy in the early United States In the early days of electricity and natural gas usage, energy utilities were not regulated. Utilities compe...