57.列出相似与区别

list similarities and differences

56.利用野牛　 make use of the bison

55.以……结束　 end up with

54.放弃　 give up

53.整个平原的野生动物链

the whole wildlife chain of the plains

52.对　……有影响have an effect on

51.相反　　 in turn

50.消失　 die out

49.靠……过活　 live on

48.掉到地上　 fall on the ground