二、bootstrap4基础（flex布局）

1.1 Flex弹性布局（一）

<div class="d-flex flex-column border border-danger  justify-content-end mb-5" style="height: 200px;">
			<div class="p-2 border border-success">one</div>
			<div class="p-2 border border-success">two</div>
			<div class="p-2 border border-success">three</div>
		</div>