A．their academic performance will affect their careers

　　 B．they want to run for positions of academic authority

　　 C．they have to observe university discipline

　　 D．they are heavily involved in student affairs

　　66．The student organizations seem to be effective in .

　　 A．dealing with the academic affairs of the university

　　 B．keeping up the students’ enthusiasm for social activities

　　 C．ensuring that the students observe university regulations

　　 D．evaluation students’ performance by bringing them before a court

　　67．Some students are enthusiastic for positions in student organizations probably because .

　　 A．they hate the constant pressure and strain of their study

　　 B．they will then be able to stay longer in the university

　　 C．such positions help them get better jobs

　　 D．such positions are usually well paid

　　D

　　Digital camera

　　 The newly invented digital camera is fascinating; you can take pictures without film. You can transfer and exhibit your picture globally in a few seconds through the Internet .The image stored in a hard drive will never wear out like the traditional photos .Digital cameras also satisfy the impatient photographer by allowing them to view their masterpiece in real time.

　　 Unlike the images of traditional cameras formed by chemical reaction ,the digital camera works as an image digitizer itself .It’s made of CCD(charge –coupled device ), a small grid of tiny light –sensitive cells .When struck by light ,each cell sends out an electrical signal whose waveform characteristics vary depending on the intensity （强度）of light .The signal from each cell is changed into a digital value and stored in the camera’s memory or on an electronic storage medium. A “picture” is reduced to a very long list of numbers waiting to be converted back into visual form. Processed through a computer ,each value becomes a pixel; pixels are reassembled in the original grid pattern and displayed or printed.

　　 The image resolution（分辨率）of a digital camera depends on the CCD. More cells on the CCD mean more pixels on the image ,which gives greater detail and higher image resolution .The early digital camera had resolution only up to 400 pixels per image ,cost several thousand dollars ,and was mainly for business use .Now there are more choices for consumers in different price ranges . The variety of digital camera has amazed first adapters to buy the products.

　　 The digital camera technology is moving very fast .A few months ago ;most of the digital cameras were equipped with focus lenses ,but now most new models are equipped with auto focus lenses at reasonable prices .With all these inventions and technology advancements ,the future of digital camera is bright ,and digital cameras may eventually replace traditional cameras.

　　68．The second paragraph mainly talks about ____________.

　　 A．how digital camera works

　　 B．what a pixel is in a digital camera