单选

There are two ways to create colors in a photograph. One method, called additive, starts with three basic colors and adds them together to produce some other color. The second method, called subtractive, starts with white light(a mixture of all colors in the spectrum)and, by taking away some or all other colors, leaves the one desired. In the additive method, separate colored lights combine to produce various other colors. The three additive primary colors are green, red, and blue(each providing about one third of the wavelengths in the total spectrum). Mixed in varying proportions, they can produce all colors. Green and red light mix to produce yellow; red and blue light mix to produce magenta; green and blue mix to produce cyan. When equal parts of all three of these primary-colored beams of light overlap, the mixture appears white to the eye. In the subtractive process, colors are produced when dye(as in paint or color photographic materials)absorbs some wavelengths and so passes on only part of the spectrum. The subtractive primaries are cyan(a bluish green), magenta(a purplish pink), and yellow. These are the pigments or dyes that absorb red, green, and blue wavelengths, respectively, thus subtracting them from white light. These dye colors are the complementary colors to the three additive primaries of red, green, and blue. Properly combined , the subtractive primaries can absorb all colors of light, producing black. But, mixed in varying proportions, they too can produce any color in the spectrum. Whether a particular color is obtained by adding colored lights together or by subtracting some light from the total spectrum, the result looks the same to the eye. The additive process was employed for early color photography. But the subtractive method, while requiring complex chemical techniques, has turned out to be more practical and is the basis of all modern color films.

37. What does the passage mainly discuss?

  • A.Recent development in camera technology.
  • B.How to make white light.
  • C.The additive and subtractive methods of producing color.
  • D.The discovery of the spectrum.
参考答案
您可能感兴趣的试题

Communication can be the most critical aspect of whether a change strategy will succeed or fail.【T1】The degree to which information flows down through the organization can influence how well the change vision is understood and embraced.It can impact the values, behaviors and mindset of the workforce. It can either clarify or muddle a company's organizational structure and employee roles and it can enhance or detract from the culture the leadership is trying to maintain.【T2】Executives who have successfully led change efforts advocate in-person discussions and meetings as the most effective communication vehicles.The degree to which information is shared across the organization can impact speed and flexibility tremendously. Lateral communication and cooperation is important to buying an innovative organization as it supports risk-taking and provides tools to take action.【T3】Continuous innovation, a critical element of e-business strategy, is at the mercy of an organization's communication structure.【T4】In today's business environment, the challenge associated with communication is not simple one of volume.Instead, it is the need to reach the target audience(both internal and external)with messages that include strategic, tactical and WIIFM laments. It is the need to prioritize the communications for the target audiences(so that the most important will be absorbed first), as well as the need to strike a balance between too little and too much information.【T5】In the e-business environment, building a relationship with customers is critical, and this cannot be achieved without hearing their suggestions, needs and desires.To be effective for internal audiences, communication must share what is and what is not changing. Communication builds commitment, and is the key to overcoming resistance to the change.

71. 【T1】

¥

订单号:

遇到问题请联系在线客服

订单号:

遇到问题请联系在线客服