Why is a less diverse ecosystem more vulnerable? ?

Having a less diverse ecosystem makes it more vulnerable because animal's diets become limited and let's say one species gets wiped out, it leaves everything else with even less food.

Answer(1)=c; expanded food and nutrition education program; answer(2)=a; elderly and those with health issues; answer(3)=nutrition program for the elderly;

  consider  the  following scenario,  then describe  how  you might conduct  a  study using  ansrs,  convenience sample, and a  voluntary response sample.  you  are  interested  in  parents'  opinion  of the  war  in  iraq.  your population  is  parents  of  high school students.  your question  is, "do you  believe that the  war  in