commute – v. regularly travel between home and work

emission – n. the act of releasing gas, heat, light, etc. out into the air

renewable – adj. any naturally occurring kind of energy, such as sunlight or wind

plummet – v. to fall very quickly in amount or value

outbid – v. to offer and pay more for something than someone else

challenge – n. something that is difficult and that tests someone's ability or determination