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已知a、b为直线,α,β,γ为平面,有下列四个命题: ①a∥α,b∥α,则a∥b...
已知a、b为直线,α,β,γ为平面,有下列四个命题:
①a∥α,b∥α,则a∥b
②α⊥β,β⊥γ,则α∥β
③a∥α,a∥β,则α∥β
④a∥b,b⊂α,则a∥α
其中正确命题的个数是( )
A.0
B.1
C.2
D.3
考点分析:
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