( C ) For centuries, elephants have captured our admiration and imaginations, and it’s easy to see why. 21 their complex brains, elephants are incredibly clever and sensitive: caring for their families and being able to remember faraway places and old pals. 22 , when elephants spot friends, they often show affection by wrapping their trunks together. Trunks come in handy for more than just greeting. 23 , elephant babies suck their trunks for comfort, just as human babies suck their thumbs. Elephants have special teeth called tusks. They use tusks to carry things, dig for roots and water, fight enemies and impress other elephants. Unfortunately, 24 those amazing tusks that put elephants’ lives at risk. The desire for tusk ivory is the reason so many elephants 25 . From the days of ancient Egypt and Rome, elephant tusk ivory has been a precious commodity. More recently, it’s been used 26 piano keys and decorative ornaments. In order to get the ivory, elephants are killed and their tusks are sawed off. In 1979, there were an estimated 1.3 million elephants in Africa. By 2007 that number 27 to between 472,000 and 690,000. Today, in many parts of the world, ivory or “white gold” remains a 28 of wealth and status, especially in Asia. With the spending power of a growing middle class in countries such as China, the demand for illegal ivory is 29 . To help stop this illegal trade in tusks, education is important. If more people 30 that every piece of ivory comes from a dead elephant, fewer people might want to buy ivory products. And less demand for ivory means more elephants will survive. 【題組】25. (A) had killed (B) had been killed (C) have killed (D) have been killed