选词填空。 that foot the fall do try they slow both of Galileo, lived in the city of Pisa, where there is a leaning tower about 180 1 high. From the top 2 the tower Galileo dropped a light ball and a heavy ball exactly at 3 same time. They 4 fell at about the same speed and hit ground together. He 5 it again and again. Every time he got the same result. At last, he decided 6 he had found the truth about 7 objects. As we know now, heavy objects and light objects fall at the same speed unless air holds 8 back. A feather falls 9 than a stone only because the air holds the feather back more than it 10 the stone. 1.______ 2.______ 3.______ 4.______ 5.______ 6.______ 7.______ 8.______ 9.______ 10.______