Question 90
In the triangle $ABC$, points $H, L, K$ are chosen on the sides $AB, BC, AC$, respectively, so that $CH \perp AB$, $HL \parallel AC$, $HK \parallel BC$. In the triangle $HBL$, let $P$ and $Q$ be the feet of the altitudes from $H$ and $B$, respectively. Prove that in the triangle $AKH$, the feet of the altitudes from $A$ and $H$ lie on the line $PQ$.