PTE  RA  38   机经 考官朗读

PTE RA 38 机经 考官朗读

2017-10-13    00'30''

主播: 海外东方学院

480 48

介绍:
. Once most animals reach adulthood, they stop growing. In contrast, even plants that are thousands of years old continue to grow new needles, add new wood, and produce cones and new flowers, almost as if parts of their bodies remained "forever young". The secrets of plant growth are regions of tissue that can produce cells that later develop into specialized tissues. 微信 hwdfxy