Final answer:
Rachel Carson wrote 'Silent Spring,' a groundbreaking work discussing the adverse environmental effects of pesticides, which influenced the environmental movement and policy changes like the DDT ban. The reference to Andrew Sullivan is ambiguous without further context, as there are multiple individuals by that name who could have diverse contributions.
Step-by-step explanation:
Rachel Carson was an influential American biologist and author who wrote the seminal work Silent Spring, published in 1962. Her book investigated the environmental impacts of widespread pesticide use, particularly DDT, linking these chemicals to detrimental effects on wildlife and human health. Her work played a critical role in the environmentalist movement, leading to the ban of DDT in the U.S. in 1972 and helping to inspire the first Earth Day celebrations.
As for Andrew Sullivan, the student's question does not specify which Andrew Sullivan is being referred to, and since there are multiple individuals with that name who could have written on various topics, it is essential to have more context to provide an accurate answer. Notably, Andrew Sullivan is a common name and could refer to the British-American author and blogger known for his political commentary or various other writers and professionals.
Both Rachel Carson's environmental advocacy and Andrew Sullivan's potential contributions reflect on our understanding of nature and society, highlighting the power of the written word to influence public opinion and policy.