【简答题】Sources of excessive greenhouse gases created by humans include driving cars, using 4)_ from coal-fired power plants or heating our homes with oil or natural gases.
【判断题】The second-generation technologies include solar heating, biomass, photovoltaics, wind power, solar thermal power stations, and modern forms of bioenergy.
【判断题】The main use of fossil fuels in ancient socio-cultural life include only three perspectives: production, the heating material, and transportation.
【简答题】Millions die early from air pollution each year. Air pollution costs the global economy more than $5 trillion annually in welfare costs, with the most serious 26 occurring in the developing world. ...
【单选题】In general, the oil mist detectors include a built-in heating unit and a compact plug for electrical connectionThe function of heating unit is to ()
A.
avoid false alarms as a result of condensing water vapor
B.
avoid danger of frost under very cold weather
C.
reduce the viscosity of the crankcase atmosphere in order to improve the fluidity
D.
keep the temperature of the oil mist detectors in an appropriate range