一、口算。
$\frac{2}{3} × \frac{2}{3} =$
$\frac{2}{3} ÷ \frac{1}{4} =$
$\frac{12}{13} ÷ \frac{16}{39} =$
$\frac{8}{9} ÷ 4 =$
$\frac{5}{4} × \frac{4}{5} =$
$\frac{5}{8} ÷ \frac{5}{9} =$
$\frac{2}{5} ÷ \frac{2}{15} =$
$\frac{6}{7} - \frac{5}{49} =$
$\frac{3}{8} × \frac{3}{4} =$
$\frac{5}{14} ÷ \frac{10}{11} =$
$\frac{5}{26} × 13 =$
$\frac{5}{6} ÷ \frac{5}{2} =$
$\frac{1}{2} ÷ \frac{2}{5} =$
$\frac{3}{4} + \frac{1}{8} =$
$\frac{7}{8} ÷ \frac{15}{16} =$
$\frac{1}{8} × \frac{1}{8} =$
$\frac{6}{7} ÷ \frac{6}{5} =$
$24 ÷ \frac{2}{5} =$
$\frac{6}{7} ÷ \frac{7}{2} =$
$\frac{8}{11} ÷ \frac{32}{33} =$
$\frac{9}{25} × \frac{5}{9} =$

1.$\frac{4}{9}$ 2.$\frac{8}{3}$ 3.$\frac{9}{4}$ 4.$\frac{2}{9}$ 5.$1$ 6.$\frac{9}{8}$ 7.$3$ 8.$\frac{37}{49}$ 9.$\frac{9}{32}$ 10.$\frac{11}{28}$ 11.$\frac{5}{2}$ 12.$\frac{1}{3}$ 13.$\frac{5}{4}$ 14.$\frac{7}{8}$ 15.$\frac{14}{15}$ 16.$\frac{1}{64}$ 17.$\frac{5}{7}$ 18.$60$ 19.$\frac{12}{49}$ 20.$\frac{3}{4}$ 21.$\frac{1}{5}$

二、计算下面各题，能用简便算法的就用简便算法。
$\frac{18}{11} ÷ \frac{5}{3} × \frac{11}{9}$
$(1 - \frac{1}{3} × \frac{2}{5}) ÷ \frac{9}{7}$
$13 × (\frac{2}{13} + \frac{2}{7}) × 7$
$60 × \frac{37}{59}$
$(\frac{5}{13} + \frac{5}{12} × \frac{6}{5}) ÷ \frac{46}{13}$
$\frac{5}{6} × 6 ÷ \frac{5}{6} × 6$

1.$\frac{6}{5}$ 2.$\frac{91}{135}$ 3.$40$ 4.$37\frac{37}{59}$ 5.$\frac{1}{4}$ 6.$36$