A．shouldn't replace scientific method with imaginative ……

单项选择题The autor wants to prove with the example of Isaac Newton that ______.

单项选择题How could Dennis distinguish between a small ball and a large ball from a distance of 3 feet The large ball would produce ______.

单项选择题How could Dennis distinguish between a book and a pillow of the same size and at an equal distance in front of him A book would produce ______.

单项选择题The writer says that a blind baby is doubly handicapped in comparison to a sighted child because ______.

单项选择题If someone holds a book 6 feet directly in front of Denis and then moves it only 1 foot directly in from of him, what change in sound does Dennis hear