(1) The left and right directrices $l_{1} 、 l_{2}$ of the hyperbola $\frac{x^{2}}{a^{2}}-\frac{y^{2}}{b^{2}}=1$ trisect the line segment $F_{1} F_{2}$ (where $F_{1} 、 F_{2}$ are the left and right foci of the hyperbola), then the eccentricity $e$ of the hyperbola is ( ).
(A) $\frac{\sqrt{6}}{2}$
(B) $\sqrt{3}$
(C) $\frac{3 \sqrt{3}}{2}$
(D) $2 \sqrt{3}$
(1) B Hint: From the given, we have $2c = 3 \times \frac{2a^2}{c}$, solving this yields $e=\sqrt{3}$.