[单项选择]A test of a hypothesis that the means of two normally distributed populations are equal based on two independent random samples:（）
A. is based on a Chi Square statistic.
B. is a paired -comparisons test.
C. is done with a t -statistic.

[单项选择]The natural order hypothesis means______. s
A. people acquire language rules in a predictable order
B. language rules must be taught in a certain order
C. language rules must be learned in a certain order
D. people tend to acquire simple rules early and difficult rules late

[单项选择]The first sentence in paragraph two means that the conclusions of the experts are ______.
A. reliable
B. easy to arrive at
C. not believable
D. remote from reality

[单项选择]

Passage Two
A rapid means of long-distance transportation became a necessity for the United States as settlement (新拓居地) spread ever farther westward. The early trains were impractical curiosities, and for a long time the railroad companies met with troublesome mechanical problems. The most serious ones were the construction of rails able to bear the load, and the development of a safe, effective stopping system. Once these were solved, the railroad was established as the best means of land transportation. By 1860 there were thousands of miles of railroads crossing the eastern mountain ranges and reaching westward to the Mississippi. There were also regional southern and western lines.
The high point in railroad building came with the construction of the first transcontinental system. In 1862 Congress authorized two western railroad companies to build lines from Nebraska westward and from California eastward to a meeting point, so as to complete a transconti
A. Settlements Spread Westward
B. The Coast-to-Coast Railroad: A Vital Link
C. American Railroad History
D. The Importance of Trains in the American Economy

[单项选择]In Paragraph 5, "two-tier system" means some ______.
A. men have many wives while others have none
B. people are very rich while others are very poor
C. people have too much work to do while others have nothing to do
D. people control others

[单项选择]Two hours ______ the limit of this test.
A. are
B. has been
C. have been
D. is

[单项选择]Now "sandwich" means ______.[A] two pieces of bread with meat between them[B] two pieces of bread between some meat[C] two pieces of bread among some meat

[单项选择]Now "Sandwich" means ______.[A] two pieces of bread with meat between them[B] two pieces of bread between some meat[C] two pieces of bread among some meat

[单项选择]This hypothesis states that environments that are too clean may actually make the ______ system develop oversensitive responses.
A. mental
B. nervous
C. immune
D. physical

[单项选择]The Sapir-Worf hypothesis is about
A. language and society.
B. language and thought.
C. second language acquisition.
D. language change.

[单项选择]Which of the following statements about hypothesis testing is TRUE A Type Ⅱ error is the probability of:（）
A. rejecting a true null hypothesis.
B. rejecting a true alternative hypothesis.
C. failing to reject a false null hypothesis.

[单项选择]The Input Hypothesis was put forward by
A. Chomsky.
B. Sapir.
C. Krashen.
D. Hymes.

[单项选择]What is implied in the efficient market hypothesis "There's no such thing as a free lunch"


A. You need to ignore a hot tip offered.
B. You need to pay for a hot tip offered.
C. You need to justify a hot tip offered.
D. You need to take quick advantage of a hot tip offere