一、口算。
$\frac{5}{6} ÷ \frac{1}{2} =$
$\frac{5}{11} ÷ \frac{6}{11} =$
$\frac{4}{9} ÷ \frac{16}{27} =$
$10 ÷ \frac{7}{8} =$
$\frac{1}{6} ÷ \frac{2}{3} =$
$4 ÷ \frac{1}{7} =$
$\frac{7}{12} ÷ \frac{3}{7} =$
$\frac{1}{7} ÷ \frac{1}{2} =$
$\frac{4}{5} ÷ \frac{5}{3} =$
$\frac{2}{3} ÷ \frac{15}{8} =$
$\frac{5}{12} ÷ \frac{10}{21} =$
$\frac{4}{5} ÷ \frac{8}{15} =$
$\frac{8}{9} ÷ \frac{7}{20} =$
$\frac{3}{4} ÷ \frac{7}{6} =$
$\frac{3}{2} ÷ \frac{15}{4} =$
$\frac{4}{9} ÷ \frac{8}{15} =$
$15 ÷ \frac{5}{3} =$
$\frac{21}{62} ÷ \frac{1}{31} =$
$\frac{5}{9} ÷ \frac{5}{4} =$
$\frac{12}{5} ÷ \frac{11}{10} =$
$\frac{5}{2} ÷ \frac{5}{6} =$

1.$\frac{5}{3}$ 2.$\frac{5}{6}$ 3.$\frac{3}{4}$ 4.$\frac{80}{7}$ 5.$\frac{1}{4}$ 6.$28$ 7.$\frac{49}{36}$ 8.$\frac{2}{7}$ 9.$\frac{12}{25}$ 10.$\frac{16}{45}$ 11.$\frac{7}{8}$ 12.$\frac{3}{2}$ 13.$\frac{160}{63}$ 14.$\frac{9}{14}$ 15.$\frac{2}{5}$ 16.$\frac{5}{6}$ 17.$9$ 18.$\frac{21}{2}$ 19.$\frac{4}{9}$ 20.$\frac{24}{11}$ 21.$3$

二、计算下面各题，能用简便算法的就用简便算法。
$( \frac{5}{4} - \frac{1}{6} ) ÷ \frac{5}{6}$
$1 - \frac{7}{16} ÷ \frac{7}{6} - \frac{5}{8}$
$[ ( \frac{3}{5} - \frac{1}{4} ) × \frac{4}{7} + 0.3 ] ÷ \frac{3}{4}$
$\frac{16}{25} ÷ \frac{1}{5} ÷ \frac{4}{5}$
$27 ÷ \frac{9}{5} + 27 ÷ 5$
$\frac{5}{7} × 21.79 - 0.79 ÷ \frac{7}{5}$

1.$\frac{13}{10}$ 2.$0$ 3.$\frac{2}{3}$ 4.$4$ 5.$\frac{102}{5}$ 6.$15$