1.The 45-year-old animal was put down by his carers at a zoo in Kenya after "age-related complications".
put down 杀死 (危险或病重的动物)
The judge ordered their dog Samson to be put down immediately.
该法官下令立即杀掉他们的狗萨姆森 。
2.There were more than 2,000 northern white rhino in the wild in the 1960s but their numbers continually dwindled because of the value of their horns.
dwindle 下降;减少
The factory's workforce has dwindled from over 4,000 to a few hundred.
该厂的工人总数已从4000多减少到了几百人 。