题干
A: What can you see? B: I can see two____.A: What colour are they? B: They're____. 
答案(点此获取答案解析）
rabbits,white
A: What can you see? B: I can see two____.A: What colour are they? B: They're____.
相对恒定 ③垂体等内分泌腺合成和分泌激素 ④维持体液的酸碱平衡