1. Microscopic organisms settle to the seafloor and accumulate in marinemud.
marine adj. 海的; 航海的; 海产的
2. The canopy ,the upper level of the trees in the rain forest, holds a plethora of climbing mammals of moderately large size, which may include monkeys, cats, civets, and porcupines.
mammals n. 哺乳动物
3. This break in Earth’s history is marked by a mass extinction, when as many as half the species on the planet became extinct.
extinction n. 消失
4. But what climate change shows us is that we are not in control, either of the biosphere or of the machine which is destroying it.
climate n. 气候
climatic adj. 气候上的
5. The world anxiously watched as, every few hours, a hurtling chunk of comet plunged into the atmosphere of Jupiter.
Jupiter n. 木星
6. Dandelions are called opportunists because they contribute to the natural processes of erosion and the creation of gaps in the forest canopy.
7. It is the work of architects to create buildings that are not simply constructions but also offer inspiration and delight.
8. To help society members better understand the forces controlling their food supply.
9. During the seventeenth and eighteenth centuries, almost nothing was written about the contributions of women during the colonial period and the early history of the newly formed United States.
10. Twice in the twentieth century, large meteorite objects are known to have collided with Earth.
11. Many factors have contributed to the great increase in desertification in recent decades.
12. Personal correspondence, newspaper clippings, and souvenirs were saved and stored.
stored vt.贮藏 n.商店
storefront n. 店面
13. By contrast, in the United States an estimated 97 million birds are killed each year when they collide with buildings made of plate glass, 57 million are killed on highways each year; at least 3.8 million die annually from pollution and poisoning; and millions of birds are electrocuted each year by transmission and distribution lines carrying power produced by nuclear and coal power plants.
14. This new form of manufacturing depended on the movement of goods to distant locations and a centralized source of laborers.
15. The exposed rocks are attacked by the various weather processes and gradually broken down into fragments, which are then carried away and later deposited as sediments.
16. It works in compression to divert the weight above it out to the sides, where the weight is borne by the vertical elements on either side of the arch.
17. Many incomplete skeletons were found but they included, for the first time in an archaeocyte, a complete hind leg that features a foot with three tiny toes.
complete v. 使齐全；完成 adj. 完整的
completely adv. 完整地; 彻底地
incomplete adj. 不完全的
complement n. 补足物
18. Given the aquifer’s low recharge rate, its use for irrigation is causing water tables to drop and will eventually lead to its depletion.
rate n.比率，率 vt.评估 vi.被评价
19. They contain remote areas where the winds rarely die down.
20. We have known about this phenomenon for a long while, and have accepted that pheromones, secreted scents, are the factor regulating the hormones.
pheromones n. 外激素