题干
We must our pets. They're our friends.
A：look at
B：look up
C：look after
D：look for
答案(点此获取答案解析）
C
We must our pets. They're our friends.
A：look at
B：look up
C：look after
D：look for
人类在保护这一濒危物种过程中取得的重大技术突破，具有里程碑意义。从联系的观点看，人工繁殖中华鲟的成功说明