因为他很聪明，所以他的成绩总是很高。 Incorrect English： “Because he is smart ，so his grades are always very high。” Correct English： “Because he is smart ，his grades are always very high。”OR“He is smart ，so his grades are always very high。” 解释： 这个问题与“问题3”非常类似。这种类型的句子，我们可以用“because”或“so”，但两者不能同时出在一个句子里，其中之一既可表达“因为。。。。。。所以。。。。。。”的意思。在表达“因果关系”的句子里，用“because”的句子与用“so”的句子并没有明显的区别。 Explanation： This problem is very similar to the problem in number 3。In a sentence of this kind，we can use “because”or “so”。We cannot use both words，as this is incorrect。One word is enough to convey the meaning . There is no real difference between the sentence with “because”and the sentence with “so”。 Examples： “Because the tea is too hot，he doesn’t want to drink it。”OR“The tea is too hot，so he doesn’t want to drink it。” “Because the Chinese economy is developing quickly，we can see rapid changes in China。”OR “The Chinese economy is developing quickly，so we can see rapid changes in China。” 注意： 在英语中有另外一种很自然的方式表达上述类型的句子，即先说结果，再用“because”引出原因。 Note： There is another very natural way to express this kind of sentence in English。We put the result first，insert the word “because”，and then put the reason last。 Examples： “His grades are always very high because he is smart。” “He doesn’t want to drink the tea because it is too hot”。 “We can see rapid changes in China because the Chinese economy is developing quickly。”