Now the boy like his parents ____ (not like) fast food at all.
设向量a→与b→的夹角为,定义a→与b→的“向量积”:a→×b→是一个向量,它的模a→×b→=a→b→sinθ,若a→=(-3,-1),b→=(1,3),则a→×b→ =( )
—How lucky he was!
读图,回答问题.