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.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.

the answers would be

the first one and the second one