听力原文： When a person draws an analogy, he or she observes similarities between two things, and usually goes on to suggest the thing which is familiar can help explain the one / which is not or is only partly understood. As in forms of logic, there is also the inference / that the similarities noted imply other probable similarities.
Scientists have often described organic processes by analogy. Some analogies are useful and accurate / as far as they go. For example, the comparison of the heart with a pump / or of the kidney with a filter / has helped illustrate the nature and function of these organs. However, analogies that have been proposed to ex plain the nervous system / have been less successful. One aspect of analogies is / that they are limited by the scientific understanding of the time. The mind cannot be compared to a computer, for instance, until there is a computer.
(1)