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设α表示平面,l,m表示两条不重合的直线,给定下列四个命题 ①l∥α,l⊥m⇒m...
设α表示平面,l,m表示两条不重合的直线,给定下列四个命题
①l∥α,l⊥m⇒m⊥α
②l∥m,l⊥α⇒m⊥α
③l⊥α,l⊥m⇒m∥α
④l⊥α,m⊥α⇒l∥m
其中正确的命题的个数是( )
A.1
B.2
C.3
D.4
考点分析:
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