A:Just leave them alone.
B:That’s right.
C:Are you sure?
D:How old are the boys?
下面词语中没有错别字的一组是( )
如图,在平行六面体ABCD﹣A1B1C1D1中,若AB→=a→,AD→=b→,AA1→=c→,则D1B→=( )
—I'm five.