Section_ⅢGrammar-_连词

　　语法图解

　　探究发现

　　①Norway is at the top of the list, while the US is at number 7.

　　②Although developed countries give some financial help, they need to give much more.

　　③In the last ten years in China, 150 million people moved out of poverty. However, the challenges are still great.

　　④The report shows that we are making some progress but that we need to make greater efforts.

　　⑤You can do it however you like.

　　⑥While he is in poor health, he works hard.

　　⑦Young as/though he is, he knows a lot.

　　[我的发现]

　　(1)由③④⑤句可知，but是一个连词，而however既可以用作副词，也可以用作连词。

　　(2)②句although引导让步状语从句，可以与though互换。

　　(3)⑥句中while引导让步状语从句，意为"虽然；尽管"，而①句中while表示对比或相反的情况，意为"然而"。

　　(4)⑦句中as/though引导让步状语从句，且句子采用了倒装语序，即将从句中的表语、状语或动词原形提至句首。

　　1．but和however的用法

两者都意为"但是；然而"，均表示转折关系，但用法有所不同。