一遍又一遍地重复句式相同、长度相似的句子会使一段话变得枯燥无味。比如：
We have received your letter of April 2.We are sorry for the wrong dispatch We will do something about it.
为了避免以上情况的发生，最好使句子结构变化多端，可通过以下方法使句子发生变化。
(1) 改变句子长度。在一段文字中运用长短句交叉，可使句子变得错落有致。试比较：
We have received your letter of 2nd July.We regret that travellers cheques are not acceptable.Please give us instructions to make a transfer.
Thank you for your letter of July 2.We are afraid that the suppliers may not accept travellers cheques for payment.Please give us instructions to make a transfer.
(2) 改变句子结构，以不同的方式来造句。
Despite our sales increase,profits fell.
Consequently,the prices came down.
To reach overseas markets,we must find better means of distribution.
(3) 改变句子的动势。不要总按照主语——谓语（动词）——补语的顺序造句。试比较：
I have received your letter of April 10.I shall be arriving in Brussels on May 2. I must return immediately after the meeting. I cannot therefore accept your invitation to dinner that evening.
Thank you for your letter of April 10. I shall be arriving in Brussels on May 2. Unfortunately, I must return immediately after the meeting, and therefore cannot accept your invitation to dinner that evening.