All cells have protein markers on their membranes, and the rh antigen is found in the membranes of red blood cells. if a person possesses the rh antigen on their red blood cells, it is indicated with a + sign. if a person does not possess the rh antigen, it is indicated with a – sign. a, b, and o refer to the abo blood groups.

Considering the attached figure which is a table; and studying the table in the figure; Giving the mother anti-rh antibodies before delivering her baby would be wise precaution in Case 1 only. Most Rh disease can be prevented by treating the mother during pregnancy or promptly after childbirth. The mother has an intramuscular injection of anti-Rh antibodies. This is done so that the feal rhesus D positive erythrocytes are destroyed before the immune system of the child can develop. 

He should put sand around the spill in order to contain it so that it won't spread

They formed the oceans.  as they melted water was formed and the water made the oceans