1. 比较下面各组分数的大小。
$\frac{5}{6}$和$\frac{4}{9}$ $\frac{5}{14}$和$\frac{9}{20}$ $\frac{6}{11}$和$\frac{1}{3}$
$\frac{3}{4}$和$\frac{4}{5}$ $\frac{10}{17}$和$\frac{3}{5}$ $\frac{5}{12}$和$\frac{4}{11}$

$​\begin{aligned}&\frac {5}{6}=\frac {15}{18}$，$\frac {4}{9}=\frac {8}{18}\\&\frac {15}{18}\gt \frac {8}{18}$，$\frac {5}{6}\gt \frac {4}{9}\end{aligned}​$
$​\begin{aligned}&\frac {5}{14}=\frac {50}{140}$，$\frac {9}{20}=\frac {63}{140}\\&\frac {50}{140}\lt \frac {63}{140}$，$\frac {5}{14}\lt \frac {9}{20}\end{aligned}​$
$​\begin{aligned}&\frac {6}{11}=\frac {18}{33}$，$\frac {1}{3}=\frac {11}{33}\\&\frac {18}{33}\gt \frac {11}{33}$，$\frac {6}{11}\gt \frac {1}{3}\end{aligned}​$
$​\begin{aligned}&\frac {3}{4}=\frac {15}{20}$，$\frac {4}{5}=\frac {16}{20}\\&\frac {15}{20}\lt \frac {16}{20}$，$\frac {3}{4}\lt \frac {4}{5}\end{aligned}​$
$​\begin{aligned}&\frac {10}{17}=\frac {50}{85}$，$\frac {3}{5}=\frac {51}{85}\\&\frac {50}{85}\lt \frac {51}{85}$，$\frac {10}{17}\lt \frac {3}{5}\end{aligned}​$
$​\begin{aligned}&\frac {5}{12}=\frac {55}{132}$，$\frac {4}{11}=\frac {48}{132}\\&\frac {55}{132}\gt \frac {48}{132}$，$\frac {5}{12}\gt \frac {4}{11}\end{aligned}​$

2. 把下面每组中的分数按照从大到小的顺序排列起来。
(1) $\frac{3}{5}$，$\frac{3}{4}$和$\frac{2}{5}$ (2) $\frac{2}{15}$，$\frac{4}{25}$和$\frac{4}{27}$
(3) $\frac{1}{2}$，$\frac{2}{3}$和$\frac{3}{4}$ (4) $\frac{11}{12}$，$\frac{5}{9}$和$\frac{5}{6}$

$​\frac {3}{4}\gt \frac {3}{5}\gt \frac {2}{5}​$
$​\frac {4}{25}\gt \frac {4}{27}\gt \frac {2}{15}​$
$​\frac {3}{4}\gt \frac {2}{3}\gt \frac {1}{2}​$
$​\frac {11}{12}\gt \frac {5}{6}\gt \frac {5}{9}​$

3. 把下面各组中的分数按照从小到大的顺序排列起来。
(1) $\frac{11}{20}$，$\frac{21}{40}$和$\frac{31}{60}$ (2) $\frac{17}{18}$，$\frac{24}{25}$和$\frac{31}{32}$

$​\frac {31}{60}\lt \frac {21}{40}\lt \frac {11}{20}​$
$​\frac {17}{18}\lt \frac {24}{25}\lt \frac {31}{32}​$