Read the excerpt from Silent Spring. On the farms the hens brooded, but no chicks hatched. The farmers complained that they were unable to raise any pigs—the litters were small and the young survived only a few days. The apple trees were coming into bloom but no bees droned among the blossoms, so there was no pollination and there would be no fruit.

What kind of tone do the underlined words create?
bewildered
threatening
courageous
insignificant