1. (2019·泰兴模拟) 阅读短文，回答问题。（每题答案不超过6个词）

    With their long tusks (象牙), elephants look strong. However, it is this feature that makes the animal endangered. Many of them are killed for their tusks. People make elephant tusks into crafts (工艺品) and jewelry and sell them to rich people.
    But can these priceless body parts grow back? The answer is no, Live Science said. The elephants' tusks are actually part of their teeth. Nearly all African elephants and most male Asian elephants have these long teeth. About one-third of the tusk is in the animal's skull (头骨). The tusk has a nerve (神经) running down its center. This makes it similar to your teeth. Once you lose a tooth, you will never grow a new one.
    Elephants use their tusks to protect themselves, lift things, dig water and gather food. But losing the tusk will not kill them. The way in which they lose the tusk is what matters. Usually, people get tusks by culling (限量捕杀), which means killing old and weak elephants. They also take tusks from the elephants that have died naturally.

    However, these sources aren't enough to keep up with the demand for ivory. Therefore, some poachers (偷猎者) kill healthy elephants and cut their faces open to remove the tusks. About 27,000 elephants are killed by poachers each year, according to National Geographic.
    As a result of poaching, some African elephants gradually evolved (进化) without tusks, which has allowed them to survive. In Mozambique, about 90 percent of African elephants were killed for their tusks and meat from 1975 to 1992, National Geographic reported.
    Scientists found that about a third of younger females—the generation born after 1992—never developed tusks.

1. （1） What do people make elephants tusks into?
3. （2） How many things can elephants use their tusks to do according to the passage?
5. （3） What do people kill the elephants for?
7. （4） How do poachers remove tusks from healthy elephants?
9. （5） What do some African elephants do in order to survive?