损益表是用以反映经营实体在一定期间利润实现(或发生亏损)的财务报表。它是一张()报表。
A.静态;
B.动态;
C.静态动态相结合;
D.总体
参考答案:B
I’m afraid nobody but his parents or Jim, his best friend, _____ the secret.
A.are going to tell
B.have told
C.has told
D.have been told
设ψ(X)=XAXT,φ(X)=XAXT是正定二次型,其中A=(aij),B=(bij),令cij=aijbij,以C=(cij)作二次型f(X)=XCXT,证明:f是正定的.