Someone answer

which methods reduce friction?
check all that apply.

1 increasing speed

2 lubricating surfaces

3using ball bearings

4 increasing surface roughness

5 using aerodynamic designs

6using nonstick materials

Friction means resistance. Friction offers resistance to a moving object or the moving parts of an object. The following  methods  help to reduce friction:

lubricating surfaces  

using ball bearings

using aerodynamic designs

using nonstick materials

Increasing surface roughness and increasing speed will actually increase friction.

i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.