[单选题]The primary source of lift is _______ .
A.the pressure differential created by movement of air about the wing
B.the atmospheric pressure around the airplane
C.the direction and speed of the wind around the airplane
D.the way the wings are attached to the fuselage

[单选题]When properly set, _______ is the primary source of heading information.
A.heading indicator
B.magnetic compass
C.turn coordination
D.attitude indicator

[单选题]_______ is the main source of lift.
A.The difference in pressure between the upper and lower surfaces of the wing
B.The difference in curvature between the upper and lower surfaces of the wing
C.The curvature on the upper portion of the wing
D.The curvature on the lower portion of the wing

[单选题]The two primary ways to control lift are changing _______ .
A.angle of attack
B.angle of incidence
C.airspeed
D.either A or C

[单选题]_______ represents the relationship between the length and width of a wing. It is one of the primary factors in determining lift/drag characteristics.
A.Aspect ratio
B.Lift-to-drag ratio
C.Load factor
D.Average chord

[单选题]The coefficient of lift is a way to measure lift as it relates to the _______ .
A.area of the wing
B.span of the wing
C.angle of attack
D.relative wind

[单选题]Lift is proportional to the square of the airplane’s velocity. If an airplane’s speed is doubled, lift increases _______ .
A.two-fold
B.three-fold
C.four-fold
D.eight-fold

[单选题]Lift is proportional to the square of the airplane’s velocity. If an airplane’s speed is reduced by one half, lift _______ .
A.is doubled
B.increases four fold
C.is decreased to one half of the previous value
D.is decreased to one quarter of the previous value

[单选题]In general, extending large angle simple flaps increases lift and drag coefficient, decreases critical angle of attack, and _______ the ratio of lift and drag.
A.increases
B.does not change
C.decreases
D.is hard to determine whether increasing or decreasing

[单项选择]The primary dissimilarity between the youth market in Europe and that in the U.S. is that______.


A. the volume of sales in Europe is more enormous than that in America
B. there are more abundant sorts of goods in Europe than in America
C. the prominent consumers in the youth market in Europe are the working youth
D. the young customers in Europe have comparatively larger purchasing power

[单项选择]What three primary colors do we see


A. Red, white, and blue.
B. Red, green, and yellow.
C. Red, green, violet.
D. Red, green, blu

[单项选择]Safety is always my primary concern.
A. secondary
B. least
C. last
D. chief

[单项选择]A) ride C) lift
B) help D) rise


A. ride
B. help
C. lift
D. rise

[单项选择]The primary purpose of the passage is to


A. explain and resolve a controversy among meteorologists
B. present and describe a recently discovered phenomenon
C. suggest and prove a theory on the cause of a phenomenon
D. describe and confirm research findings under question
E. (E) discuss and evaluate the soundness of certain experimental observations

[单项选择]The primary objective of Basic Econometrics is to provide an elementary but an comprehensive introduction to the art and science of econometrics.
A. brief
B. precise
C. simplified
D. extensive

[单项选择]

Usually the primary purpose of textbook writing is to inform. In textbooks, authors wellinformed in a particular subject or discipline identify the terms, facts, and opinions considered essential to an understanding of the field. While authors’ personal interests play a role in what terms or facts are selected and how they are interpreted, the writing bears a primary or central goal which is not to persuade you to see things from the same perspective. In fact, textbook authors frequently give equal time to opposing points of view so that readers can draw their own conclusion.
However, as you turn from your textbooks to the pages of newspapers and magazines, you may encounter writers with other primary goals. Some write to entertain; others write simply to air a personal preference. However, a good portion of the writers you encounter, particularly on the editorial (社论) pages, write in the hope that you will share or at least seriously consider adopting their
A. Textbook writers are usually better informed in their subjects.
B. Textbook writers are more objective than other types of writers.
C. Editorials aim at sharing facts with the readers.
D. All magazine articles have the aim to share opinions with the readers.