The ideal expository graf contains a topic sentence followed by others which explain or amplify the first.

理想的说明段落应该以概括性句子起头，接下去的句子解释或者详述第一句的内容。

But it wasn't to last. It sounded too similar to the aristocratic title 'graf' -- which

但是“grave”注定持续不了： 它与当时的贵族称号'graf'发音太相近了。

The opening graf is of the classic type, beginning with a topic sentence that is supported by the sentences which follow.

开头一段是经典结构，主题句打头，后面的句子支持这个主题。