四级阅读过程中常见的几类“信号词”：
　　1.以下词组提示下文所涉及的重要信息：
　　The main / important point / conclusion / reason….
　　The point to note here…
　　2.以下词组提示了下文的结构框架：
　　There are three major reasons…
　　3.but 和 however表示对比，常常用来提示重要信息，例如：
　　The rising birth rate is not due to increased fertility, but to a sharp decline in the death rate.
　　4.在文中提问可以突出问题后的答案，提示读者答案中有重要信息，例如：
　　Why is a piped water supply so important? Disease due to contaminated water is a common cause of death in childhood.
　　5.有时，为了保证读者完全理解自己的观点，作者会在文中反复提出自己的观点，例如：
　　Death control can be achieved autonomously. In other words, the death rate can be cut without anything else changing.
　　6.文章的结论通常是非常重要的，因此，读者要在文中寻找提示结论的“信号词”，例如：
　　Thereforethe result
　　In conclusionwe can conclude
　　One of the primary conclusions
　　7.举例是为了帮助读者理解某一个观点，因此，文中的例子不是浏览文章时的重要信息。在阅读过程中，以下词组提示读者下文是举例部分信息。
　　For example/instancelike
　　Such asthese include
　　To illustrateamong these are
　　有时，作者也会用破折号或括号来提示举例信息，例如：
　　The developing countries are dependent on cash crops – sugar, coffee, cacao, cotton.
　　Precipitating/violent/unexpected factors are those which reduce the food supply (droughts, floods, wars, epidemics)…
　　在段落浏览时，读者在看到信号词后，应不断对下文信息作出相应的判断，例如：
　　The main reason for (提示：下文信息重要) the reduction in the death rate in the developing world has been improved public health measures. For example, (提示：下文信息不重要，仅仅是为了用来证明前面的观点) in Sri Lanka the death rate was halved over ten years by spraying the mosquitoes which carry malaria.
　　Why (提示：问题的答案中有读者应该关注的重点) is it so easy to cut the death rate in this way and yet so hard to reduce the birth rate? One answer (提示：这只是众多答案中的一种，并不是最重要的。) is that public health measures can be very cheap. Anti-malarial spraying is inexpensive. But this is not the important point (提示：but后面的是非常重要的信息).
　　For birth control programmes to be successful, a change in attitude is required, whereas death control can be achieved autonomously. In other words, (提示：这里是作者想要强调的重要信息) the death rate can be cut without anything else changing.