Herschel observed that an otherwise colourless solution of _________ in water emitted a blue colour under certain circumstances.

研制出HEMA材料,并发明旋转成形技术的科学家是( ) A: Thomas Young B: John Herschel C: Otto Wichterle D: August Muller

Match each description (1-9) with the appropriate person.changed<br/>his mind about the number of galaxies in the universe() A: Pythagoras B: Hipparchus C: Galileo D: Thomas Wright E: William Herschel F: Christopher Wren G: Jacobus Kapteyn H: Edward Barnard I: Harlow Shapley J: Heber Curtis K: Karl<br/>Jansky L: John Hey