Mary is____a ballet. [ ]
A.looking
B.seeing
C.looking at
D.watching
答案:D
90-3527+403=9______(判断对错)
理财产品A与理财产品B的收益率相关系数是0.5,这说明当理财产品A的收益率提高1%时,理财产品B的收益率将提高0.5%。( )