Developing and Developed Countries

2) the uk is in the thirteenth position, while china is in the middle of the list.
3) although more than 80% of children in developing countries go to primary school, about 115 million children are not being educated.
4) although developed countries give some financial help, they need to give much more.
q1. which sentences compare two facts?
q2. which sentences can you rewrite using the word but?
suggested answers:
q1. all of them.
q2. all of them.
step 2. explanation.
a. but and however
but 作為并列連詞，在意義上起轉折作用。 but 前后的兩個句子或短語在意義上形成鮮明對照。 but 用來連接兩個分句或兩個較長的短語時， but 前面一般要加逗號。例如：
　　（ 1 ） he is old but strong. 他年紀雖大卻很強壯。
　　（ 2 ） learning the guitar isn't difficult, but you will have to practise.
　　     學彈吉他并不難，但是你得練習。
　　（ 3 ） he tried， but could not do it. 他試過，但是干不了。
　however 意為“可是，然而，盡管”，較 but 的意味弱，通常用作連接性狀語。其位置可以在句首，句末或插入句中。當其被用來對照兩個分句時，中間需要有一個逗號；當它被用作句子的插入語時，則前后應各有一個逗號。例如：
　　（ 4 ） however，we need not do that now. 可是，我們現在不需要做那個。
　　（ 5 ） he said it was so；he was mistaken，however. 他說是那樣的，然而他卻弄錯了。
　　（ 6 ） his friends，however，had other ideas. 然而他的朋友們卻另有見解。
　　注： however 也可用作連接副詞，意為“不論怎樣”，用來引導讓步狀語從句。例如：
　　however we may do it，it will be a difficult job. 無論雪下得多大，我們都必須回去。
b. although and while
  while表示兩個事實之間的轉折對比，although可以用but改寫成另一種句子
while 用作連詞時，連接兩個并列句子，表示“對比”關系。例如：
　　he went out for a walk， while i stayed at home.
　　（他出去散步了，而我卻呆在家里。）
　　i like singing while she likes dancing.
　　（我喜歡唱歌，而她喜歡跳舞。）
　　you like sports， while i prefer music.
（你喜歡體育，而我更喜歡音樂。）
although引導的從句放在主句前后均可，有時還可放在句中。
although many difficulties are still ahead, we are determined to make greater achievements.
盡管在前面的道路上還有許多困難，但是，我們決心要取得更大的成就。
he often helps me with my english although he is quite busy.
盡管他相當忙，但是還常常幫我學英語。
although引導的從句不能與but, however連用，但可與yet, still連用。不能說：although he was old, but he worked hard. 應把but去掉。當然，保留but而去although也可。
c. conclusion
 1，but與 however,
相同點：都表示轉折，都可以連接兩個句子
不同點: ①but還可連接兩個并列的成分，however不能；