Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions

Rachel Carson was born in 1907 in Springsdale, Pennsylvania. She studied biology at college and zoology at Johns Hopkins University, where she received her master’s degree in 1933. In 1936, she was hired by the U.S. Fish and Wildlife Service, where she worked most of her life.

Carson’s first book, Under the Sea Wind, was published in 1941. It received excellent reviews, but sales were poor until it was reissued in 1952. In that year she published The Sea Around Us, which provided a fascinating look beneath the ocean’s surface, emphasizing human history as well as geology and marine biology. Her imagery and language had a poetic quality. Carson consulted no less than 1,000 printed sources. She had voluminous correspondence and frequent discussions with experts in the field. However, she always realized the limitations of her nontechnical readers.

In 1962, Carson published Silent Spring, a book that sparked considerable controversy. It proved how much harm was done by the uncontrolled, reckless use of insecticides. She detailed how they poison the food supply of animals, kill birds and fish, and contaminate human food. At the time, spokesmen for the chemical industry mounted personal attacks against Carson and issued propaganda to indicate that her findings were flawed. However, her work was proved by a 1963 report of the President’s Science Advisory Committee.

(Source: TOEFL Reading)

The passage mainly discusses Rachel Carson’s work ______________.