When can a girl become pregnant? O when she first ovulates
O when she first menstruates
O when she has been menstruating for about a year
O after her second period

The cell reaction uses external supplies of a full and an oxidant, which are consumed and needs to be provided continuously. the cell will continue to provide electrical energy so long as there is a supply of fuel and oxidant.  hope this ! (:  

Answer(550) lb (1) foot each second