The noun field has several meanings. You have learned one meaning. Give two other meanings for field.

Often on a topographic map, every fifth contour line is darkened. what is this line called? a. key b.slope c.benchmark d. index contour

Which one of the following is an oxidation-reduction reaction? naoh + hno3 --> h2o + kno3 naoh + hno3 --> h2o + kno3 so3 + h2o --> h2so4 cacl2 + na2co3 --> caco3 + 2 nacl ch4 + 2 o2 --> co2 + 2 h2o al2(so4)3 + 6 koh --> 2 al(oh)3 + 3 k2so4

All of the following describe uses of nonrenewable energy sources except