治理黄河的根本措施在于
A:兴建蓄洪分洪工程
B:上游修建水库
C:中游搞好水土保持
D:下游加固大堤
若向量 a→ =(1,1), b→ =(2,﹣1), c→ =(﹣1,2),则 c→ 等于( )
下列关于保护生物物种多样性的做法或措施不科学的是( )
After a heated discussion at the meeting,a new plan came________being,which would have a great effect________the culture life of people.