A． is not the worst of the negative consequences resulting from the use of pesticides
B． now occurs most frequently among all accidental deaths
C． has sharply increased so as to become the center of public attention
D． is unavoidable because people can't do without pesticides in farming

A． limited exposure to them does little harm to people's health
B． the present is more important for them than the future
C． the danger does not become apparent immediately
D． humans are capable of withstanding small amounts of poisoning

A． people find invisible diseases difficult to deal with
B． attacks by hidden enemies tend to be fatal
C． diseases with obvious signs are easy to cure
D． people tend to overlook hidden dangers caused by pesticides