In paragraph 2, the author uses this extreme language: "A few years earlier, an ad like this would have been unthinkable." How does the author's choice of the word unthinkable convey people's attitude toward women in the workplace at the time? in the hidden figures text

Which statement contains an opinion? the ants serve to protect the acacia from other plants and herbivores. the acacia depends on pollinators for the exchange of genetic material. the acacia has no chemical defenses to discourage herbivores. the ants provide the acacia with the best protection from other plants and herbivores.