一、口算。
$\frac{6}{7} ÷ \frac{3}{7} =$
$10 × \frac{11}{4} =$
$\frac{9}{10} ÷ \frac{1}{5} =$
$\frac{3}{4} × \frac{3}{5} =$
$\frac{6}{7} ÷ \frac{2}{17} =$
$\frac{2}{7} × 0.14 =$
$\frac{10}{9} ÷ \frac{9}{7} =$
$2 - \frac{4}{15} =$
$\frac{5}{16} ÷ \frac{1}{4} =$
$\frac{2}{5} ÷ \frac{3}{5} =$
$30 ÷ \frac{5}{6} =$
$\frac{3}{7} ÷ \frac{4}{5} =$
$\frac{1}{2} + \frac{5}{4} =$
$\frac{5}{6} ÷ \frac{11}{12} =$
$\frac{2}{3} - \frac{3}{5} =$
$\frac{5}{18} ÷ \frac{10}{9} =$
$\frac{3}{7} ÷ \frac{8}{21} =$
$\frac{5}{6} ÷ \frac{2}{5} =$
$\frac{3}{2} ÷ \frac{5}{4} =$
$\frac{17}{24} × \frac{16}{51} =$
$\frac{3}{2} ÷ \frac{2}{3} =$

$2$
$\frac{55}{2}$
$\frac{9}{2}$
$\frac{9}{20}$
$\frac{51}{7}$
$0.04$
$\frac{70}{81}$
$1\frac{11}{15}$
$\frac{5}{4}$
$\frac{2}{3}$
$36$
$\frac{15}{28}$
$\frac{7}{4}$
$\frac{10}{11}$
$\frac{1}{15}$
$\frac{1}{4}$
$\frac{9}{8}$
$\frac{25}{12}$
$\frac{6}{5}$
$\frac{2}{9}$
$\frac{9}{4}$

二、计算下面各题，能用简便算法的就用简便算法。
$\frac{1}{3} + ( \frac{3}{4} - \frac{2}{3} ) ÷ \frac{1}{5}$
$12 × ( \frac{1}{12} + \frac{3}{16} ) × 16$
$\frac{22}{13} - \frac{3}{2} × \frac{3}{10} - \frac{11}{20}$
$\frac{2}{5} ÷ [ \frac{5}{11} × ( \frac{9}{10} + \frac{1}{5} ) ]$
$( \frac{3}{8} - \frac{1}{3} + \frac{5}{6} ) ÷ \frac{1}{24}$
$\frac{3}{11} × \frac{3}{4} + \frac{3}{11} ÷ 4$

$\frac{3}{4}$
$52$
$\frac{9}{13}$
$\frac{4}{5}$
$21$
$\frac{3}{11}$