Geologists have studied the way that heat flows from the earth.地质学家曾研究过热量如何散出地球。We need helpers of all types, engineers, scientists (e.g. geologists) and teachers.我们需要各方面的帮手：工程师、科学家（例如地质学家）和教师。By drilling, geologists can...
a spotless white shirt洁白的衬衣A spotless stove told us that his mother is a diligent housekeeper.炉子清洁无瑕就表明他母亲是个勤劳的主妇.Each morning cleaners make sure everything is spotless...每天早晨，清洁工们会把一切都打扫得干干净净。Each morning cleaners make ...