1. The golden mole is threatened by habitat destruction and environmental changes caused by the workings of a mine. They are adapted to living in underground environments, and their habitats are often located where mining operations occur.
2. The pine marten and polecat live on borrowed time because their habitats are being destroyed or altered, and they face threats from human activities such as hunting and deforestation. Since the pine marten and polecats are constantly having to relocate their habitats and search for new grounds, their chances of survival are greatly reduced. Coupled with the accelerated rate of deforestation, the pine marten and polecats don't have much chance of continued survival.
3. Hippos are vulnerable to the harmful actions of illegal poachers who target them for their meat, teeth, and bones, all of which hold significant value on the black market. As large animals with relatively slow movement, they spend a considerable portion of their lives in or near water. This behaviour makes them susceptible to being hunted by poachers who can easily locate and shoot them. 
4. In the case of cheetahs in Botswana, the population of these big cats in that region are declining due to habitat loss, human-wildlife conflict, and hunting. The phrase "watch their last setting suns" suggests a sense of finality, as if the cheetahs are on the brink of extinction and may not survive much longer.

a. Illegal poachers hunt and kill animals without permission or in violation of local, national, or international laws. They typically target endangered or protected species for their valuable body parts, such as tusks, horns, skins, or bones, which can be sold on the black market for high prices. Poachers also hunt animals for their meat, either for personal consumption or to sell.

b. The phrase "Do the cheetahs of Botswana watch their last setting suns?" is a metaphorical way of asking whether the cheetahs in Botswana are on the brink of extinction due to various human-induced threats, such as habitat loss, poaching, or human-wildlife conflict. The "last setting suns" symbolize the potential end of the cheetah population in Botswana, creating a sense of urgency and concern for their survival.

c. One literary device used in these lines is personification. The poet attributes human-like qualities to the cheetahs by suggesting that they "watch" the setting sun. This personification evokes empathy from the reader, making it easier to relate to the plight of the cheetahs and understand the gravity of their situation.