On a vessel，if someone fell overboard and you did not know over which side the person fell，you should（）.

A.immediately reverse the engines

B.stop the propellers from turning and throw a ring buoy over the side

C.increase speed to full to get the vessel away from the person

D.first put the rudder hard over in either direction

影响毒性作用的因素有（）、（）、（）三个方面。