What is a precummer?

What type of rhetorical device has been employed in these lines? Different streams of education? How has the history of scientific research made an impact on society? What is 9mm in centimeters? Is a fish-eye lens convex? How do you wash clothes with a washing machine? What can provide a temperature rise of 40degrees Celsius? How much fossil fuels does the US use? What is another term for applied science? Can the motion of an object be measured by looking at it? How many kilograms are there in 60 grams? Is urea a base in water but acid in liquid ammonia? What can be caused by acids produced by plant roots? What comprises the scientific method? Which science mainly applies to crash dynamics? What were some negative effects of rapid industrial growth? How many cc is a Yamaha R15? What 25 Celsius in Fahrenheit? When do children walk? Can we apply the evolutionary concept 'survival of the fittest' to human beings?