div 只显示两行超出部分隐藏

        .td_div{ width: 234px;height: 52px;overflow: hidden;text-overflow: ellipsis; display:-webkit-box;  -webkit-line-clamp: 2; -webkit-box-orient: vertical;line-height: 26px }

                    <td rowspan="2" colspan="2" ><div class="td_div" ><p>Firefox with a new engine, whether you start 10 or 1000 tabs, gets faster when switchiwhether you start 10 or 1000 tabs, gets faster when switching.</p></div></td>