3、位,若,则的值等于(C)A.-6B.-2C.2D.62.设向量且,则锐角为(B)A.B. C. D.3.“”是“直线与圆相交”的(A)A.充分而不必要条件B.必要而不充分条件C.充分必要条件D.既不充分也不必要条件4.函数的图象大致为(C)beconsistentwithinthesamedisk.Alternateunifiedcorerequirementsplacedontheterminalstripterminals,onlineidentityandensurethecoppercoreisnotexpose