Solar panels, wind turbines, hydro power and geothermal energy and hydrocarbons (natural gas or coal) can all be used to produce hydrogen (a primary energy).

Energy industry is the totality of all of the industries involved in the production and sale of energy, including fuel extraction, manufacturing, （ ） and distribution.

There is further to go in routinely including women when designing and ___ energy access strategies. A: implementing B: involving C: preparing D: including

The study makes clear that air emissions even at levels below those commonly held to be acceptable are potentially ________ to the health of inner-city residents.

中国大学MOOC: Most scientists in the world today firmly believe the effective means to stop global warming is to reduce emissions of air _____.