如何在td中设置文本行（换行）的最大数量？

<table border="3">
        <tr> <td class="table_class">111111 222222 333333 </td> <td class="table_class">234 </td> </tr>
        <tr> <td class="table_class">2321</td> <td class="table_class">ssS</td> </tr>
    </table>

.table_class {
    width: 20px;
}
<table border="3">
        <tr> <td class="tabl