8. In a right trapezoid $A B C D$, $A D / / B C, \angle A$ $=90^{\circ}, A B=7, A D=2, B C=3, E$ is on the line segment $A B$, and $\triangle E A D$ is similar to $\triangle E B C$. Then the number of such points $E$ ( ).
(A) is exactly one
(B) is two
(C) is three
(D) is more than three
8.C.

Let $A E=x$, then $E B=7-x$. From the condition $\frac{x}{2}=\frac{7-x}{3}$, we get $x=\frac{14}{5}$. Also, from the condition $\frac{x}{2}=\frac{3}{7-x}$, we get two solutions for $x$.