计算下面各题。
$\frac{2}{13} - \frac{2}{11} × \frac{11}{13}$
$\frac{24}{35} × \frac{7}{8} × \frac{10}{11}$
$63 × \frac{2}{9} + 63 × \frac{6}{7}$
$\frac{11}{20} × \frac{10}{3} - \frac{5}{6}$
$\frac{22}{7} × \frac{2}{11} + \frac{3}{7}$
$\frac{3}{4} + \frac{1}{4} × \frac{2}{3} + \frac{1}{3}$
$2 - \frac{8}{15} × \frac{3}{4}$
$\frac{5}{26} × ( \frac{1}{4} + \frac{5}{6} )$
$\frac{13}{18} × ( \frac{11}{13} × \frac{26}{5} - \frac{21}{5} )$
$1 - ( \frac{3}{4} - \frac{1}{2} ) × \frac{2}{5}$
$( \frac{3}{4} - \frac{3}{16} ) × ( \frac{2}{9} + \frac{1}{3} )$
$\frac{8}{9} × [ \frac{2}{3} × ( \frac{5}{8} - \frac{5}{16} ) ]$
$\frac{1}{9} + \frac{8}{9} × \frac{3}{4}$
$\frac{4}{21} × \frac{7}{4} + 5.4 × \frac{1}{6}$
$\frac{4}{7} × [ 0.75 - ( \frac{7}{16} - 0.25 ) ]$

1. 0
2. $\frac{6}{11}$
3. 68
4. 1
5. 1
6. $\frac{5}{4}$
7. $\frac{8}{5}$
8. $\frac{5}{24}$
9. $\frac{13}{90}$
10. $\frac{9}{10}$
11. $\frac{5}{16}$
12. $\frac{5}{27}$
13. $\frac{7}{9}$
14. $\frac{37}{30}$
15. $\frac{9}{28}$