单选题 The human ear contains the organ for hearing and the organ for balance. Both organs involve fluid-filled channels containing hair cells that produce electrochemical impulses when the hairs are stimulated by moving fluid. The ear can be divided into three regions: outer, middle, and inner. The outer ear collects sound waves and directs them to the eardrum separating the outer ear from the middle ear. The middle ear conducts sound vibrations through three small bones to the inner ear. The inner ear is a network of channels containing fluid that moves in response to sound or movement. To perform the function of hearing, the ear converts the energy of pressure waves moving through the air into nerve impulses that me brain perceives as sound. Vibrating objects, such as the vocal cords of a speaking person, create waves in me surrounding air. These waves cause the eardrum to vibrate with the same frequency. The three bones of the middle ear amplify and transmit the vibrations to the oval window, a membrane on the surface of the cochlea, the organ of hearing. Vibrations of me oval window produce pressure waves in the fluid inside me cochlea. Hair cells in the cochlea convert the energy of the vibrating fluid into impulses that travel along the auditory nerve to the brain. The organ for balance is also located in the inner ear. Sensations related to body position are generated much like sensations of sound. Hair cells in the inner ear respond to changes in head position with respect to gravity and movement. Gravity is always pulling down on the hairs, sending a constant series of impulses to the brain. When the position of the head changes—as when the head bends forward—the force on the hair cells changes its output of nerve impulses. The brain then interprets these changes to determine the head's new position.

单选题 What can be inferred about the organs for hearing and balance?

【正确答案】 B

【答案解析】解析：事实细节题。选项A与C在文中未提及。由第四段第一句“The organ for balance is also locatedin the inner eat”可排除D选项。第一段第二句提及两个器官都通过含有毛细胞的通道，并且这些毛细胞在受刺激时会产生电化学冲击波，由此可知答案为B。

单选题 Hearing involves all of the following EXCEPT______.

单选题 It can be inferred from Paragraphs 2 and 3 that the cochlea is a part of______.

【正确答案】 D

【答案解析】解析：信息推理题。文章第四段第一句中的the cochlea，the organ of hearing说明cochlea(耳蜗)是听力器官，该段之后作者又解释说声波振动如何从中耳传播到耳蜗的薄膜(oval window)，然后再通过听力神经传播到大脑。在第五段首句提及平衡器官也位于内耳，由此可推知cochlea(耳蜗)位于中耳。故答案为D。

单选题 What can be inferred from Paragraph 4 about gravity?

【正确答案】 A

【答案解析】解析：信息推断题。第四段首句提及平衡器官位于内耳。之后指出，体位感知的产生正如声音感知的产生，内耳中的毛细胞会对头部位置的变化做出反应，而这些变化又与重力和运动相关。之后详细说明重力是如何影响脑部的位置变化的。选项A中提及重力对于平衡感起到了举足轻重的作用，与文章信息一致。故答案为A。