He is very dear to us. We have been prepared to do whatever it takes to save his life.
A:ready
B:possible
C:afraid
自然选择保留的变异永远都有利于该生物的生存.(判断对错)
看图选一选:
A.粗 B.细 C.像绸布 D.软 E.硬 F.像鞭子
狼的尾巴____ 狗的尾巴____
牛的尾巴____ 老鼠的尾巴____
老虎的尾巴____ 金鱼的尾巴____