該問題中，(A)泛指經濟規律，面過寬;(C)和(D)只是供需規則的二個單獨的方面不能包含全部，面太窄。正確的答案是(B)，因為這正是該短文自始至終談論的主題。

　　例六：

　　Directions: Read the following passage and select the most appropriate title:

　　According to legend, the gods of the ancient Greeks lived in the clouds on the top of Mount Olympus. Zeus, the father of the gods, carried a bolt of lightning in his hand and ruled like an earthly king. Apollo was the sun god and his beams were golden arrows; he shielded the flocks of sheep and the fields of grain. Athena was the warrior goddess, standing in shining armor ready to protect the Greek cities. There were other gods as well, all with familiar human characteristics, but these were the leading gods.

　　(A) The Gods of the Ancient Greeks

　　(B) The Legend of the Sky God Zeus

　　(C) Beliefs of the Ancient Greeks

　　(D) Religions of the Past

　　該問題中，(B)項只是文中提到的一項具體內容，作為主題思想面太窄了。(C)和(D)項泛指，面太寬。只有(A)項才概括了全文要說明的問題，是全文的主題。

　　三、一段文章的中心思想常常由主題句(Topic Sentence)表達。主題句常常位于段首或段尾處，間或出現在段落中間。同樣，一篇文章的中心思想也常常在開始段或結尾段點出。因此在閱讀中，我們要特別注意文章的開頭或結尾。

　　例七：

　　English is clearly an international language. It is spoken by pilots and airport control operators on all the airways of the world. Over 70 percent of the world's radio programs are in English

　　本段主題句為首句，其后的內容均說明首句。

　　例八：

　　Some students prefer a strict teacher who tells them exactly what to do. Others prefer to be left to work on their own. Still others like a democratic discussion type of class. No one teaching method can be devised to satisfy all students at the same time

　　本段中心思想在結尾句得到體現，它是此段內容的結論。

　　例九：

　　For adults a cold is not that serious. However, this is not the case for children. Cold symptoms in children may be signs of more serious diseases and should be given prompt medical attention.

　　本段主題句為第二句，因為在however后面才是作者真正的看法，并在本文中進一步作了說明。

　　然而，我們也常常發現，有的主題思想并非直接由一、二個句子表述，而是在文中間接暗示著。這就需要讀者根據文中細節進行概括與歸納，找出主題思想。