-My parents our home for a few hours when I arrived. I didn't meet them.-You could call them if you wanted to know where they were.
A:have been away from
B:had been away from
C:had left
D:had gone
萝卜、桔子等蔬菜水果放久了会空心,口感也会越来越差.这是因为在存放期间这些蔬菜水果仍然要进行____.从而消耗掉了部分有机物造成的.
若两个非零有理数a,b,满足|a|=a,|b|=﹣b,a+b<0,则a,b的取值符合题意的是( )