Although ethics classes are common around the world, scientists are unsure if their lessons can actually change behavior; evidence either way is weak, relying on contrived laboratory tests or sometimes unreliable self-reports.
尽管伦理课程在全球范围内很常见，但科学家们不确定这些课程是否真的能改变行为；无论哪方面的证据都很薄弱，依赖于人为设计的实验室测试，或者有时不可靠的自我报告。
But when Swetnam enrolled in graduate school at the University of Arizona's Laboratory of Tree-Ring Research, he was surprised to find a record of repeated blazes dating back hundreds of years before European colonists arrived on the continent.
但当斯威特纳姆进入亚利桑那大学的树木年轮研究实验室读研究生时，他惊讶地发现，早在欧洲殖民者到达大陆数百年之前，就有重复的火灾记录。
例句取自历年考研英语真题，翻译为机器生成，仅供学习参考。