如图所示是飞机机翼的截面图，当飞机在高空中水平飞行时，机翼上方气流的速度____

已知两圆的半径分别是一元二次方程x²-7x+12=0的两根，若这两个圆的圆心距为5，则这两圆的位置关系是（　　）

A．相离

B．外切

C．相交

D．内切

腹腔空腔脏器与实质性脏器破裂的主要区别点是：（）

A.外伤史

B.腹痛程度

C.有无移动性浊音

D.腹膜刺激征的程度

E.腹腔穿刺液性质

患者女性，55岁，双手不能紧握，腕关节痛，见“鹅颈征”，低热，咽痛，查血常规示：WBC12×10⁹/L，PLT430×10⁹/L，Hb89g/L。未查RF，临床诊断类风湿关节炎。

临床上所指的“鹅颈征”是指

A．腕关节

B．手近指关节

C．手远指关节

D．第一跖趾关节

E．颈椎

（）反映固体电介质自身的耐电强度。

A.击穿电压

B.击穿场强

C.介质厚度

D.绝缘强度

When butterfat was considered nutritious and healthful, a law was enacted requiring that manufacturers use the term "imitation butter" to indicate butter whose butterfat content had been diminished through the addition of water. Today, it is known that the high cholesterol content of butterfat makes it harmful to human health. Since the public should be encouraged to eat foods with lower rather than higher butterfat content and since the term "imitation" with its connotations of falsity deters many people from purchasing products so designated, manufacturers who wish to give reduced-butterfat butter the more appealing name of "lite butter" should be allowed to do so.
Which one of the following, if true, most seriously undermines the argument

A．The manufacturers who prefer to use the word "lite" instead of "imitation" are motivated principally by the financial interest of their stockholders.

B．The manufacturers who wish to call their product "fire butter" plan to change the composition of the product so that it contains more water than it now does.

C．Some individuals who need to reduce their intake of cholesterol are not deterred from using the reduced-butterfat product by the negative connotations of the term "imitation."

D．Cholesterol is only one of many factors that contribute to the types of health problems with which the consumption of excessive amounts of cholesterol is often associated.

E．(E) Most people deterred from eating "imitation butter" because of its name choose alternatives with a lower butterfat content than this product has.