我喜欢的动物 My Favorite Animal
I like dogs, because they are man's good friends.They can do many helpful things to us, such as guarding our houses, greeting guests, helping the police, and so on.Some trained dogs can even lead the blind people and save people's lives.So they're treated as our family members.I hope someday dogs will be in great harmony with human-beings.
答：海洋食物链是指在海洋生物社群中，从自营性细菌或光合作用形成的有机物开始，经浮游生物、草食性动物至各级肉食性的动物，依次形成捕食者与被食者的需求关系。食物链的结构...详情>>
