One hypothesis regarding the extinction of dinosaurs is that a meteor hit the earth causing an explosion so powerful that dust blocked the sun. why would this have caused a mass extinction?

What are four key elements of the study of economics?

25) a student takes four samples of a white crystalline solid and places each in a well plate. on top of each sample, she carefully places 20 drops of clear mystery liquids a, b, c and d. her results for each well are: liquid a: the solid dissolves quickly. liquid b: the solid appears unchanged. liquid c: a brownish colored liquid is produced. liquid d: fizzing occurs and the well becomes warmer. in which well does a physical change occur?

Name the organs of humanelemintary canal.