9.
如图,点A、D分别在两条直线y=3x和y=x上,AD∥x轴,已知B、C都在x轴上,且四边形ABCD是矩形,则$\frac{AD}{AB}$的值是( )
0 297055 297063 297069 297073 297079 297081 297085 297091 297093 297099 297105 297109 297111 297115 297121 297123 297129 297133 297135 297139 297141 297145 297147 297149 297150 297151 297153 297154 297155 297157 297159 297163 297165 297169 297171 297175 297181 297183 297189 297193 297195 297199 297205 297211 297213 297219 297223 297225 297231 297235 297241 297249 366461
| A. | $\frac{1}{3}$ | B. | $\frac{2}{3}$ | C. | 3 | D. | $\frac{3}{2}$ |