单项选择题

Directions: There are 10 questions in this part of the test. Read the passage through. Then, go back and choose one suitable word or phrase marked A, B, C, or D for each blank in the passage. Mark the corresponding letter of the word or phrase you have chosen with a single bar across square brackets on your Machine-scoring Answer Sheet.
Does walking on the moon make life better for people on earth 1 all the problems of our own world, why should we be spending huge sums on trips to outer space Such questions as these are often asked, especially 2 those whose tax money is paying for space explorations. The answers to these questions are many and varied.
Up to now, the practical benefits resulting 3 space research have included the development of new methods and skills, new processes, new services, new products, and even new companies created to make use of what 4 through space travel. Also among the benefits are better education (especially in scientific subjects), 5 management, higher quality of industrial products, and more rapid economic growth. People all over the world are now served by 6 weather predictions, better communication systems, and better understanding of the earth and its environment. Everyone will benefit 7 observations from space make it possible to measure the earth’s resources and 8 whether or not they are being used properly. 9 the space program will help our world deal with the problems of the environment. It has already brought a new appreciation of the complex system 10 man is only a part.

A. which
B. for which
C. among which
D. of which