45.
(A) Originally
(B) Fortunately
(C) Respectively
(D) Secretly

  The design of many engineering systems can be a fairly complex process. Many assumptions must be made to develop models that can be subject to analysis by the available methods and the models must be 41 by experiments. Many possibilities and factors must be considered during the problem formulation 42 . Economic considerations play an important role in designing cost-effective systems. To complete the design of an engineering system, designers from different fields of engineering must find ways to 43 . For example, the design of a passenger car requires cooperation among structural, mechanical, automotive, electrical, human factors, chemical, and hydraulics design engineers. Thus, in a(n) 44 environment considerable interaction is needed among various design teams to complete the project. In addition to the design of a system, developing procedures to measure the performance of a system is essential. A measure of performance is to be optimized while satisfying all constraints as well as ensuring quality. 45 , the revolution in computer technology allows today’s computers to perform complex calculations and process large amounts of data rapidly both for initial design and later performance measure.