5. 指代题

练习题：

（1）       When small fish venture too close to the tentacles of these "living flowers", they are stung and eaten.

（2）       The male seals do not journey so far. They swim only to the islands and there the cycle begins again.

（3）       The mountain's summit is broad and rounded. It is 14,410 feet above sea level and has an area of about one square mile.

（4）       Although wagon trains had been used to haul freight and passengers between the Eastern seaboard and the Ohio Valley since 1812, they were first used extensively in the 1820's on the Santa Fe Trail.

（5）       The clownfish even builds its nest where the anemone can protect it.

（6）       X-rays allow art historians to examine paintings internally without damaging them.

（7）       Florists often refrigerate cut flowers to protect their fresh appearance.

（8）       Some of their baskets were completely covered with shell pendants; others with feathers that made the baskets' surfaces as soft as the breasts of birds.

（9）       Some skilled craftspeople made intricately carved wooden ornamentations for furniture or architectural decorations, while others carved wooden shop signs and ships' figureheads.

（10）   Many adults, poor and disillusioned with farm life, were lured to the cities by promises of steady employment, regular paychecks, increased access to goods and services, and expanded social opportunities. Others were pushed there when new technologies made their labor cheap or expendable.

（11）   Some species, for example, begin by dropping the outermost primary feathers on each side and wait until the replacement feathers are about one-third grown before shedding the next outermost, and so on. Others always start with the innermost primary feathers and work outward.

（12）   The principal difference between urban growth in Europe and in the North American colonies was the slow evolution of cities in the former and their rapid growth in the latter. In Europe they grew over a period of centuries form town economies to their present urban structures. In North America, they started as wilderness communities and developed to mature urbanism in little more than a century.

（13）   The energy content of food is stored in the chemical bonds that link its atoms and molecules.

（14）   In the past, biologists considered mushrooms and other fungi as a type of non-free  plant. Today, however, they are most commonly regarded as a separate kingdom of living things.

Animal Congregation

     Many types of animals combine the advantages of family association with those conferred by membership in still larger groups. Bees congregate in hives; some fish move in schools; ants gather in mounds; wolves live in packs; deer associate in herds. The main Line advantage of membership in a mass community is the safety that it provides. A large group (5)  of prey may be easier for a predator to find at any given point than is a small one, and a predator may think twice before taking on such a group; if a predator does decide to challenge a large group, it may merely encounter a confusing mass of moving bodies and possibly may not succeed in its primary goal.

1. The word those in the passage refers to

  (A) types

  (B) animals

  (C) advantages

  (D) groups

2. The word it in line 4 refers to

  (A) advantage

  (B) membership

  (C) community

  (D) safety

3. The word one in the passage refers to

  (A) group

  (B) prey

  (C) predator

  (D) point

4. The word it in line 7 refers to

  (A) predator

  (B) group

  (C) mass

  (D) goal

参考答案：

1-4：C、B、A、A

New World Epidemics

    A huge loss of life resulted from the introduction of Old World diseases into the Americas in the early sixteenth century. The inhabitants of the Americas were separated from Asia, Africa, and Europe by rising oceans following the Ice Ages, and, as a result, they were isolated by means of this watery barrier from numerous virulent epidemic diseases that had developed across the ocean, such as measles, smallpox, pneumonia, and malaria. Pre-Columbian Americans had a relatively disease-free environment but also lacked the antibodies needed to protect them from bacteria and viruses brought to America by European explorers and colonists. A devastating outbreak of disease the strikes for the first time against a completely unprotected population is known as a virgin soil epidemic. Virgin soil epidemics contributed to an unbelievable decline in the population of native inhabitants of the Americas, one that has been estimated at as much as an 80 percent decrease of the native population in the centuries following the arrival of Europeans in the Americas.

10. The word they in the passage refers to

   (A) the inhabitants

   (B) epidemic diseases

   (C) rising oceans

   (D) the Ice Ages

11. The word that in the passage refers to

   (A) a disease-free environment

   (B) this watery barrier

   (C) virulent epidemic diseases

   (D) the ocean

12. The world them in the passage refers to

   (A) pre-Columbian Americans

   (B) the antibodies

   (C) bacteria and viruses

   (D) European explorers and colonists

13. The word one in the passage refers to

   (A) a virgin soil epidemic

   (B) an unbelievable decline

   (C) the population of native inhabitants

   (D) the arrival of Europeans

参考答案：

10-13：A、C、A、B