讓讀者清楚的知道這是文章結論，在文章用某種過渡詞或者連接詞來明確告訴作者，這是文章的最後一段。 The lava emitted in eruptions at Mount Nyiragongo is unusually fluid which can be made of melilite nephelinite. It truly is an alkali-rich kind of volcanic rock. the unusual chemical composition of which m