Question

已知直線m⊥平面a，直線n⊥平面b，則下列命題正確的是

1. A.
   a⊥b?m⊥n
2. B.
   a⊥b?m∥n
3. C.
   m⊥n?a∥b
4. D.
   m∥n?a⊥b

Answer 1

D