A fold observed in layers of sedimentary rock most likely resulted from the
A: converging of crustal plates.

Many cars are equipped with a catalytic converter, a device that helps remove hydrocarbons and oxides from car exhaust. As a result, this device helps to
A: decrease the production of smog.

Which activity is directly regulated by neurons?
A: the beating of the heart

If a book sitting on a flat table starts to move horizontally, it is most likely moving because
A:
an unbalanced force is being applied.