三显示自动闭塞区段，在进站信号机前方第一架通过信号机柱上应涂（）条黑斜线A、一 B、

粪类圆线虫的感染期为

A．杆状蚴

B．感染性棘头体

C．丝状蚴

D．棘头体

E．虫卵

当前盘当前目录下有数据库：学院.dbc，其中有“教师”表和“学院”表。

为“学院”表增加一个字段“老师人数”的SQL语句是（）。

A．CHANGE TABLE学院ADD教师人数I

B．ALTER STRU学院ADD教师人数I

C．ALTER TABLE学院ADD教师人数I

D．CHANGE TABLE学院INSERT教师人数I

因为恐龙是爬行动物，所以科学家们曾经认为，像今天所有生活着的爬行动物一样，恐龙是冷血动物。然而。最近在北极北部发现的恐龙化石使一些研究者认为至少有一些恐龙是温血动物。这些研究者指出只有温血动物才能经受得住北极冬季严寒的气候，而冷血动物在极冷的情况下会被冻死。
下面哪一点如果正确的活，最能削弱研究者的论证( )

A．今天的爬行动物一般都生活在温和甚至是热带的气候范围内。

B．那些化石显示北极恐龙比其他已知种类的恐龙小得多。

C．发现在一起的恐龙化石的数量表明恐龙群是如此地庞大，以至于它们需要迁移以找到一个可持续供给食物的地方。

D．北极恐龙的化石是在极其耐寒的植物化石旁被发现的。

对确定急性HBV感染最有意义的是（）

A.抗-HBcIgM阳性，抗-HB-cIgG阴性

B.HBsAg阳性，抗-HBe阳性

C.HBsAg阳性，HBeAg阳性

D.抗-HBs阳性，抗-HBcIgG阴性

E.抗-HBs阳性，抗-HBcIgG阳性

The questions in this group are based on the content of a passage. After reading the passage, choose the best answer to each question. Answer all questions following the passage on the basis of what is stated or implied in the passage.

Of all aspects of Indian culture, the caste system is perhaps the most bewildering to outsiders. For visitors unaccustomed to this system of hereditary social divisions, the complex and mostly unwritten rules governing whom a person can marry, what kind of work she can do, and even what kind of food she can eat may seem puzzling and mysterious. One reason for this confusion is that the concept of caste is actually divided into two separate but related concepts in Indian culture: varna and jati.

Varna, which literally means "color," is the most basic social division. There are four varna: the Brahmans, the traditional priest class; the Kshatriya, the warrior class; the Vaishya, the skilled workers and merchants; and the Sudra, laborers whose role is to serve the three higher classes. Below the Sudra are a class known as the Untouchables, who technically fall outside of the varna system because they are supposedly "unclean" in a ritual sense. The Untouchables are the lowest class in India, but they make life possible for everyone else because they take care of the jobs that would "pollute" the higher classes, such as working with dead animals or cleaning sewage. The Indian statesman Mohandas Gandhi, in an effort to promote social equality, encouraged people to refer to Untouchables as the Harijan, which means "Children of God."

Each varna is then divided into hundreds or thousands of jati, a term that literally means "birth." The jati are kinship groups with hereditary roles and professions, such as leatherworker or brick-maker. Observant Hindus have traditionally married within their varna and jati.

The origins of the caste system are obscure. The prevailing theory among anthropologists is that the Varna system emerged shortly after the so-called Aryan Invasion of the second millennium B.C. According to this theory, a population of Indo-European invaders conquered northern India around 1500 B.C. The Indo-Europeans placed themselves in the three highest rungs of society (Brahman, Kshatriya, and Vaishya), corresponding to the traditional division of Indo-European societies into priests, warriors, and commoners, while placing the conquered local populations into the worker classes of the Sudra and the Untouchables. This theory does not account for the jati system, however, which has parallels in no other Indo-European society. Most anthropologists suggest that the jati system predates the varna system, and that it might have originated in the Harappan civilization that prevailed in northern India prior to the Aryan Invasion.

What can we infer about the intentions of Mohandas Gandhi from the mention of him in the passage ？（）

A. He wished to switch the respective socioeconomic positions of the highest and the lowest castes in Indian society.

B. He desired the reconciliation of India with Pakistan.

C. He rejected the so-called Aryan Invasion in favor of an autochthonous explanation for the roots of Indian culture.

D. He supported the cultural dominance of the Brahman "priest" caste over the Kshatriya "warrior" caste.

E. He wished to free a class of people from the stigma of an unfavorable name.