An investor would most likely expect commodities to have correlations with traditional stock or bond investments and inflation, respectively, that are: Correlation with inflation Correlation with traditional stock or bond investments()

A. positive positive

B. positive negative

C. negative positive

在机械加工中，孔即将钻穿时，容易造成（）或钻孔质量降低的不良现象。

A.钻头折断

B.孔钻不穿

C.钻孔放大

D.钻头变形