試題詳解

45. Mosquitoes resistant to the pesticide DDT first appeared in India in 1959 and are now found worldwide. What is the most likely explanation for the global spread of DDT resistance?
(A) Mosquitoes in different regions learned to avoid DDT independently.
(B) DDT directly caused mutations in mosquitoes, making them resistant.
(C) Resistant mosquitoes migrated from India to other parts of the world.
(D) All mosquitoes gradually developed resistance over time due to exposure to DDT.
(E) DDT resistance was present in all mosquito populations but only became apparent after DDT was widely used.