Recycling solid wastes is an example of
a) utilizing covercropping techniques
b) preventing erosion in a landfill
c) eliminating sulfur pollutants in the atmosphere
d) conserving natural resources without harming the environment

Which of these is a drawback of using natural gas? a. it is fairly safe for use in homes.b. it burns more cleanly than crude oil products.c. scientists have developed new ways of extracting it.d. during its extraction, groundwater can be contaminated.