单项选择题
A.n1>n2B.n1<n2C.qi+qt=90度D.qi>qt
A.1.000B.1.200C.1.414D.1.707
A.n1>n2且qi3aresin(n1/n2)B.n1>n2且qi3arestg(n1/n2)C.n1>n2且qi3aresin(n2/n1)D.n1>n2且qi3aretg(n2/n1)