摘要：..是任意非零并且互相不共线.则在下列四个命题中:⑴(·)·-(·)·=0,⑵||-||<|-|,⑶(·)·-(·)·不与垂直,⑷(3+2)·(3-2)=9||2-4||2,真命题有----------------------------------( ) (A)⑴⑵ (B)⑵⑶ (C)⑶⑷ (D)⑵⑷

网址：http://m.1010jiajiao.com/timu3_id_4461366[举报]