1.

1. Match the words that are used in the video:

1.              attractive

a.                 force

2.               massive

b.              fourth

3.              a black

c.               from falling

4.              gravitational

d.              attracted

5.              one

e.               Newton

6.              massless

f.               to the mass

7.              keeps us

g.              particles

8.              gravitationally

h.              hole

9.              Isaac

i.                object

10.          proportional

j.                forces