interested!

For D i am confused, if some don't live in the suburbs, why can we not say some do live in the suburbs? where else would they live?

How can we assume that the poison wasn't successful in ridding the pike?

I thought it was able to, but since the negative externalities of the water being tainted for months and the region's economy suffering, they couldn't continue the practice. But, the evidence could be interpreted either way, and to me, it seems most strong that the poison IS effective.