双语例句：
Scientists continue to push back the boundaries of human knowledge.
科学家不断扩大人类知识的范围。
He is a writer first and a scientist second.
他首先是作家，然后才是科学家。
Scientists have established a connection between cholesterol levels and heart disease.
科学家已证实胆固醇含量与心脏病之间有关联。
Scientists have a fairly negative attitude to the theory.
科学家对这个理论的.态度是相当消极的。
Scientists are on the brink of making a major new discovery.
科学家很快就会有新的重大发现。