第一块将< script> 标记写入页面.我认为，如果代码全部放在一个块中，则不能保证在执行第二部分代码之前会先加载写入的< script> .

The first block writes a <script> tag to the page. I think if the code was all in one block there would be no guarantee the written <script> would be loaded before the second part of the code executed.

通过使用两个块，写入的< script> 将在第二个块执行之前加载(包含 _gat 对象).

By using two blocks, the written <script> will load (which contains the _gat object) before the second block executes.