Why is ddt still controversial?
it is still not clear whether ddt harms the environment.
despite the documented scientific effects on the environment, ddt is still
highly effective in controlling malaria.
despite the documented scientific effects on malaria, ddt's environmental
effects are uncertain.
rachel carson's findings, in her book silent spring, are questioned by many
scientists.

Cold case files recently began re-investigating an old murder case. the murder took place in the park; a young man, james, was hit over the head with a brick and killed. police suspected the jealous former boyfriend of james' wife, karen. whoever killed james may have washed their hands in a near-by bird bath as detectives found blood in the bird bath. since the murder took place before dna fingerprinting was available, the suspected killer, ronnie, went free. detectives are now reviewing the blood evidence using dna fingerprinting. based on the dna fingerprints of all possible suspects, who is james' killer?