文章是通過(guò)篇章來(lái)表達(dá)思想和主題，但篇章的構(gòu)建又需要詞與句子作為它的基礎(chǔ)材料。如果說(shuō)主題思想是文的靈魂的話，那么句就是文的血管脈絡(luò)了。脈絡(luò)不通，文也就難成文了。作文時(shí)，考生一定要注意一下幾條原則：
（一）主題句原則 來(lái)源：考試大
一個(gè)好的主題句是文章成功的一半。不僅文章有主題，段落有綱，句也必有中心。文章失卻主題，就會(huì)不知所云；落無(wú)綱，則一盤(pán)散沙，句缺中心，就無(wú)意義。所以，在立足于篇章時(shí)，一定要首先明確文的主題；在發(fā)展段落時(shí)，也要首先寫(xiě)好主題句。從PETS三的特點(diǎn)來(lái)考慮，主題句是置于文首或段首，這樣讓人一目了然！ 以下就是兩個(gè)實(shí)用的開(kāi)門見(jiàn)山式發(fā)展主題句的方法。
●To begin with, we must attach the greatest importance possible to this issue/fact (key word).
●As is well known to all, it is now high time that we took this (topic word) into serious consideration.來(lái)源：考試大
（二） 句式變化原則
好的文章動(dòng)靜結(jié)合、張弛有度有節(jié)奏感。句式也是一樣，要有變化性，這不僅能使文章更生動(dòng)，也是語(yǔ)言表達(dá)方式的需要和表達(dá)能力的體現(xiàn)。句式的變化，主要是要注意兩點(diǎn)：
● 不要從頭至尾使用一種句型。
● 長(zhǎng)短句結(jié)合。
由于語(yǔ)言功底的欠缺和慣用思維，很多人寫(xiě)的文章一種句式到頭，如：
I think …
I hope…
He does it.
He will take it
這樣的文章雖然意思表達(dá)出來(lái)了，卻顯得呆板，欠生動(dòng)。解決的辦法是：
1．間或使用主從復(fù)句。
Because he is very much determined, he will carry it out this time. (原因)
比較：He is very much determined. He will carry it out this time.
2．使用分詞結(jié)構(gòu)句。
The weather being fine, a large number of people went sightseeing.
比較：The weather is fine. A large number of people went sightseeing.
Africa is the second largest continent, its size being about three times that of China.
比較：Africa is the second largest continent. Its size is about three times that of China.
3．使用不定式句。
To be or not to be, that is a question. (莎士比亞)
To study or not to study, that is much different.(引申)
To do it well, you must plan it well.
比較：You want to do it well. And you must plan it well.
4．倒裝句來(lái)源：考試大
Only when we fully recognize its importance can we have control of its essence.
比較：After we fully recognize its importance, we can have control of its essence.
No sooner had he arrived home than it began to rain.
比較：He arrived home. And it began to rain.
5．失衡句
whether or not he will come is still unknown to all the people present.
比較：No one present knows whether he will come or not.
That he has done it all by himself is known to everyone.來(lái)源：考試大
比較：Everyone knows that he has done it all by himself.
當(dāng)然，句子并不是越長(zhǎng)越好，也不是越復(fù)雜水平就越高。凡事皆有度。太多長(zhǎng)句的堆砌讓人覺(jué)得是買弄。有時(shí)侯，一個(gè)短小精辟的句子可以起到畫(huà)龍點(diǎn)睛的作用。特別是在文末段尾。比如：
●As a creature, every one knows.
●Actions speak louder than words
●Practice makes perfect.
（一）主題句原則 來(lái)源：考試大
一個(gè)好的主題句是文章成功的一半。不僅文章有主題，段落有綱，句也必有中心。文章失卻主題，就會(huì)不知所云；落無(wú)綱，則一盤(pán)散沙，句缺中心，就無(wú)意義。所以，在立足于篇章時(shí)，一定要首先明確文的主題；在發(fā)展段落時(shí)，也要首先寫(xiě)好主題句。從PETS三的特點(diǎn)來(lái)考慮，主題句是置于文首或段首，這樣讓人一目了然！ 以下就是兩個(gè)實(shí)用的開(kāi)門見(jiàn)山式發(fā)展主題句的方法。
●To begin with, we must attach the greatest importance possible to this issue/fact (key word).
●As is well known to all, it is now high time that we took this (topic word) into serious consideration.來(lái)源：考試大
（二） 句式變化原則
好的文章動(dòng)靜結(jié)合、張弛有度有節(jié)奏感。句式也是一樣，要有變化性，這不僅能使文章更生動(dòng)，也是語(yǔ)言表達(dá)方式的需要和表達(dá)能力的體現(xiàn)。句式的變化，主要是要注意兩點(diǎn)：
● 不要從頭至尾使用一種句型。
● 長(zhǎng)短句結(jié)合。
由于語(yǔ)言功底的欠缺和慣用思維，很多人寫(xiě)的文章一種句式到頭，如：
I think …
I hope…
He does it.
He will take it
這樣的文章雖然意思表達(dá)出來(lái)了，卻顯得呆板，欠生動(dòng)。解決的辦法是：
1．間或使用主從復(fù)句。
Because he is very much determined, he will carry it out this time. (原因)
比較：He is very much determined. He will carry it out this time.
2．使用分詞結(jié)構(gòu)句。
The weather being fine, a large number of people went sightseeing.
比較：The weather is fine. A large number of people went sightseeing.
Africa is the second largest continent, its size being about three times that of China.
比較：Africa is the second largest continent. Its size is about three times that of China.
3．使用不定式句。
To be or not to be, that is a question. (莎士比亞)
To study or not to study, that is much different.(引申)
To do it well, you must plan it well.
比較：You want to do it well. And you must plan it well.
4．倒裝句來(lái)源：考試大
Only when we fully recognize its importance can we have control of its essence.
比較：After we fully recognize its importance, we can have control of its essence.
No sooner had he arrived home than it began to rain.
比較：He arrived home. And it began to rain.
5．失衡句
whether or not he will come is still unknown to all the people present.
比較：No one present knows whether he will come or not.
That he has done it all by himself is known to everyone.來(lái)源：考試大
比較：Everyone knows that he has done it all by himself.
當(dāng)然，句子并不是越長(zhǎng)越好，也不是越復(fù)雜水平就越高。凡事皆有度。太多長(zhǎng)句的堆砌讓人覺(jué)得是買弄。有時(shí)侯，一個(gè)短小精辟的句子可以起到畫(huà)龍點(diǎn)睛的作用。特別是在文末段尾。比如：
●As a creature, every one knows.
●Actions speak louder than words
●Practice makes perfect.