2019年托福考试阅读考前经典素材3

很多考生对阅读都是又爱又恨，因为他是我们提分的关键点，但是想要获得高分并非易事，小编为大家整理了这篇阅读试题，在坦途网托福考试频道还有很多相关的试题内容和托福考试时间，现在我们就一起来看看这篇文章吧！

The nervous system of vertebrates is characterized by a hollow, dorsal nerve cord that ends in the head region as an enlargement, the brain. Even in its most primitive form this cord and its attached nerves are the result of evolutionary specialization, and their further evolution from lower to higher vertebrate classes is a process that is far from fully understood. Nevertheless, the basic arrangements are similar in all vertebrates, and the study of lower animals gives insight into the form and structure of the nervous system of higher animals. Moreover, for any species, the study of the embryological development of the nervous system is indispensable for an understanding of adult morphology.

In any vertebrate two chief parts of the nervous system may be distinguished. These are the central nervous system (the nerve cord mentions above), consisting of the brain and spinal cord, and the peripheral nervous system, consisting of the cranial, spinal, and peripheral nerves, together with their motor and sensory endings. The term autonomic nervous system refers to the parts of the central and peripheral systems that supply and regulate the activity of cardiac muscle, smooth muscle, and many glands.

The nervous system is composed of many millions of nerve and glial cells, together with blood vessels and a small amount of connective tissue. The nerve cells, or neurons, are characterized by many processes and are specialized in that they exhibit to a great degree the phenomena of irritability and conductivity. The glial cells of the central nervous system are supporting cells collectively termed neuroglia. They are characterized by short processes that have special relationships to neurons, blood vessels, and connective tissue. The comparable cells in the peripheral nervous system are termed neurilemmal cells.

1. What does the passage mainly discuss?

(A) The parts of a neuron

(B) The structure of animals' nerve

(C) The nervous system of vertebrates

(D) The development of the brain

2. According to the passage , the nerve cord of vertebrates is

(A) large

(B) hollow

(C) primitive

(D) embryological

3. The author implies that a careful investigation of a biological structure in an embryo may

(A) Improved research of the same structure in other species

(B) A better understanding of the fully developed structure

(C) Discovering ways in which poor development can be corrected

(D) A method by which scientists can document the various stages of development

4. The two main parts of the central nervous system are the brain and the

(A) sensory endings

(B) cranial nerve

(C) spinal cord

(D) peripheral nerves

5. All of the following are described as being controlled by the autonomic nervous system EXCEPT

(A) connective tissue

(B) cardiac muscle

(C) glandular activity

(D) smooth muscle

6. In what lines does the author identify certain characteristic of nerve cells?

(A) lines 1-2

(B) lines 9-12

(C) lines 12-14

(D) lines 16-18

PASSAGE 44 CBBCA D

这篇文章的到这里就结束了，相信大家在这里多少都会学到一些新的内容，小编做为大家坚实的后背力量，会不断为大家整理更多的考试素材和相关内容，希望通过大家的努力最终在托福考试中都能取得自己理想的成绩！