① 研究描述：研究对象 → 方面1 / 方面2

TPO 09 - Reflection in Teaching
TPO 11 - Ancient Egyptian Sculpture
TPO 14 - Children and Advertising
TPO 15 - A Warm Blooded Turtle
TPO 22 - Spartina
TPO 26 - Energy and the Industrial Revolution
TPO 29 - Characteristics of Roman Pottery
TPO 30 - Role of Play in Development
TPO 33 - Railroads and Commercial Agriculture in Nineteenth Century
TPO 43 - The Empire of Alexander the Great
TPO 45 - Wind pollination
TPO 47 - Roman Cultural Influence on Britain   

② 研究叙述：研究对象  阶段1 → 阶段2

TPO 02 - Early Cinema
TPO 06 - Powering the Industrial Revolution
TPO 09 - The Arrival of Plant Life in Hawaii
TPO 12 - Transition to Sound in Film
TPO 16 - Development of the Periodic Table
TPO 19 - Succession Climax and Ecosystems
TPO 29 - The History of Waterpower
TPO 34 - Islamic Art and the Book
TPO 34 - The Development of Steam Power
TPO 40 - Ancient Athens
TPO 46 - The Origins of Writing    

③ 对比分类：研究对象 → 分类1 / 分类2

TPO 04 - Deer Populations of the Puget Sound
TPO 07 - Ancient Rome and Greece
TPO 12 - Water in the Desert
TPO 13 - Types of Social Groups
TPO 16 - Planets in Our Solar System
TPO 17 - Animal Signals in the Rain Forest
TPO 17 - Symbiotic Relationships
TPO 20 - Fossil Preservation
TPO 28 - Buck Rubs and Buck Scrapes
TPO 32 - Plant Colonization
TPO 42 - Callisto and Ganymede
TPO 45 - Feeding Strategies in the Ocean    

④ 现象解释：研究对象 → 解释1 / 解释2

TPO 02 - Desert Formation
TPO 05 - The Cambrian Explosion
TPO 06 - Infantile Amnesia
TPO 08 - The Rise of Teotihuacán
TPO 10 - Variations in the Climate
TPO 10 - Seventeenth - Century European Economic Growth
TPO 18 - Industrialization in the Netherlands and Scandinavia
TPO 18 - Lightning
TPO 20 - Westward Migration    

TPO 21 - Autobiographical Memory
TPO 24 - Moving into Pueblos
TPO 29 – Competition
TPO 31 - Savanna Formation
TPO 32 - Siam 1851–1910
TPO 40 - Latitude and Biodiversity
TPO 42 - Explaining Dinosaur Extinction
TPO 48 - Chinese Population Growth
TPO 48 - Climate and Urban Development    

⑤ 问题解决：解决困难 → 方法1 / 方法2

TPO 04 - Petroleum Resources
TPO 13 - Methods of Studying Infant Perception    

⑥ 观点论证：观点看法 →  证据1 / 证据2

TPO 01 - The Origins of Theater
TPO 02 - The Origins of Cetaceans
TPO 07 - The Geologic History of the Mediterranean
TPO 09 - Colonizing the Americas via the Northwest Coast
TPO 11 - Begging by Nestlings
TPO 11 - Orientation and Navigation
TPO 12 - Which Hand Did They Use
TPO 14 - Pastoralism in Ancient Inner Eurasia
TPO 15 - Mass Extinctions
TPO 21 - The Origins of Agriculture
TPO 26 - Sumer and the First Cities of the Ancient Near East
TPO 31 - Speciation in Geographically Isolated Populations
TPO 34 - Protection of Plants by Insects
TPO 41 - Trade and Early State Formation
TPO 43 - The Origin of Petroleum
TPO 46 - Ecosystem Diversity and Stability    

① Even in the areas that retain a soil cover, the reduction of vegetation typically results in the loss of the soil's ability to absorb substantial quantities of water.

② In some regions, the increase in desert areas is occurring largely as the result of a trend toward drier climatic conditions.

③ There is little doubt, however, that desertification in most areas results primarily from human activities rather than natural processes. 

① 从外形上都呈现出“正面描绘”的特点：The majority of three-dimensional representations, whether standing, seated, or kneeling, exhibit what is called frontality: they face straight ahead, neither twisting nor turning.

② 材质方面，通常是由石头、木材和金属做成的：Statues were normally made of stone, wood, or metal.

③ 用途：The function of these is quite different.

最起初，人们通过自然界的流水用来减轻人力、牧畜的工作负担（Moving water was one of the earliest energy sources to be harnessed to reduce the workload of people and animals.）；

接着，人们发现了流水的妙用而制造了水轮用以灌溉（No one knows exactly when the waterwheel was invented, but irrigation systems existed at least 5,000 years ago, and it seems probable that the earliest waterpower device was the noria, a waterwheel that raised water for irrigation in attached jars.）；

后来，为满足需求发明了水力磨来研磨谷物（The earliest waterpower mills were probably vertical-axis mills for grinding corn, known as Norse or Greek mills, which seem to have appeared during the first or second century B.C.）；

单单研磨谷物已不能满足多样的需求，人们利用水力同步发展了采矿、炼铁、造纸以及棉毛纺织工业（Raising water and grinding corn were by no means the only uses of the waterpower mill, and during the following centuries, the applications of waterpower kept pace with the developing technologies of mining, iron working, paper making, and the wool and cotton industries.）；

后来十九世纪电力工业的崛起及设施齐备的发电厂的建立，水力发电迅速发展起来（The capacity of individual power stations, many of them hydro plants, rose from a few kilowatts to over a megawatt in less than a decade.）。

从巴基斯坦北部发掘到了最古老的鲸鱼化石 Pakicetus，科学家发现了其实则为食肉哺乳动物和鲸类动物的过渡型（Other features, however, show experts that Pakicetus is a transitional form between a group of extinct flesh- eating mammals, the mesonychids, and cetaceans.）；

人们在古地中海残留的沉积物中发现了另一类早期鲸鱼 Basilosaurus，其必定是完全水生的鲸鱼，它们的后肢已经不起任何作用，或者说已经退化（Basilosaurus was undoubtedly a fully marine whale with possibly nonfunctional, or vestigial, hind legs.）；

后来对目前已经灭绝的鲸鱼 Ambulocetus natans 的发现强有力的证明了陆栖哺乳动物和海洋鲸类的联系（It was undoubtedly a whale that linked life on land with life at sea.）。