单选题 It is easy to lose patience with science today. The questions are pressing: How dangerous is dioxin? What about low-level radiation? When will that monstrous earthquake strike California? And why can't we predict weather better? But the evidence is often described "inconclusive, " forcing scientists to base their points of view almost as much on intuition as on science.
When historians and philosophers of science listen to these questions, some conclude that science may be incapable of solving all these problems any time soon. Many questions seem to defy the scientific method, an approach that works best when it examines straightforward relationships. If s0mething is done to variable A, what happens to variable B? Such procedures can, of cuurse, be very difficult in their own ways, but for experiments, they are effective.
With the aid of Newton's laws of gravitational attraction, for instance, ground controllers can predict the path of a planetary probe—or satellite—with incredible accuracy. They do this by calculating the gravitational tugs from each of the passing planets until the probe speeds beyond the edge of the solar system. A much more difficult task is to calculate what happens when two or three such tugs pull on the probe at the same time. The unknowns can grow into riddles that are impossible to solve. Because of the turbulent and changing state of the earth's atmosphere, for instance, scientists have struggled for centuries to predict the weather with precision.
This spectrum of questions—from simple problems to those impossibly complex—has resulted in nicknames for various fields of study. "Hard" sciences, such as astronomy and chemistry, are said to yield precise answers, whereas "soft" sciences, such as sociology and economics, admit a great degree of uncertainty.

单选题 Which of the following best tells what this passage is about?
A. How the large variety of factors scientists deal with makes absolute scientific accuracy impossible.
B. How Newton solved the problem of accuracy and science.
C. How "hard" science is more important than "soft" science.
D. Why historians do not study astronomy.

单选题 According to the passage, it can be inferred that the scientific method would work best in which of the following situations?
A. Predicting public reactions to a set of policy decisions.
B. Identifying the factors that will predict a California earthquake.
C. Predicting the amount of corn that an acre will yield when a particular type of fertilizer is used.
D. Calculating how much a cubic centimeter of water will weigh when cooled under controlled conditions.

单选题 According to the passage, "hard" science can be distinguished from "soft" science by which of the following characteristics?
A. Seeking precise answers to its questions.
B. Identifying important questions that need answers.
C. Making significant contributions to human welfare.
D. Creating debates about unresolved issues.

单选题 The author implies that when confronted with complex questions, scientists base their opinions ______.
A. on theoretical foundations
B. more on tuition than on science
C. on science and tuition, in varying degrees
D. on observations and past experience