（1） 段落的统一性 英语段落有一大特点，即一个段落只涉及一个主题（甚至只是一个主题的某个方面）。段落中的一个句子点出主题并说明作者对该主题的看法，而其它所有句子都是为展开该主题而给出的事实、例证、推理，它们与主题紧密相关。段落中不应有一个与主题无关的句子。英文段落的这种各个句子与主题的关联性被称作段落的统一性。请看以下两例： (1) Birds build their nests in all kinds of places. Some are high in trees, on the sides of buildings or on the top of hills while others on the ground, in fields or by stream banks. Birds also use various nesting materials to build their nests, including sticks, mud, stones, . Some birds are able to change to be suitable for different conditions. They’ll build their nests wherever they can find a spot and use whatever materials they can find. But other birds will build their nests only in certain places and use only certain materials. (2) "Culture shock" occurs as a result of lack of understanding in a new culture. It happens to people who have been suddenly "transplanted abroad". Newcomers may be anxious because they do not speak the language, know the customs, or understand people’s behavior in daily life. The visitor finds that "yes" may not necessarily mean "yes," that friendliness does not always mean friendship, or that statements that appear to be serious are really intended as jokes. The foreigner may be unsure as to when to shake hands or embrace, when to initiate conversations, or how to approach a stranger. The notion of "culture shock" help explain feelings of bewilderment and disorientation. Language problems do not account for all the frustrations that people feel. When one is deprived of everything that was once familiar, such as understanding a transportation system, knowing how to register for university classes, or knowing how to make friends, difficulties in coping with the new society may arise.