重点讲解：
1. wear down (使)磨平；(使)磨光；
The machines start to wear down, they don't make as many nuts and bolts as they used to.
机器开始出现磨损，螺母和螺钉的产量不如从前了m0I%00&GW;。
2. even though 即使；尽管；纵然；
She never took a taxi, even though she could afford to.
尽管她坐得起出租汽车，但她从未坐过=eHmaQ#+W!Fj!WBX。
3. pick up 拿起；提起；拾起；捡起；
She bent down to pick up her glove.
她俯身去捡手套9)#u,sf9B2Pd,e0dVv。
4. go extinct 灭绝；绝种；
Most animals went extinct because of evolution.
大部分动物的绝迹是因为进化演变之故reh5|XnXzYBe&。