9. 如图,在三棱锥D−ABCD-ABCD−ABC中,侧面ACD⊥ACD\botACD⊥底面ABCABCABC,AC=DAAC=DAAC=DA,AC⊥BCAC\bot BCAC⊥BC,AF⊥BDAF\bot BDAF⊥BD,CH⊥BDCH\bot BDCH⊥BD,EEE是CDCDCD的中点.(1)证明:AE⊥AE\botAE⊥平面DBCDBCDBC;(2)证明:CH//CH//CH//平面AEFAEFAEF.