What is one of the causes of mechanical weathering acid rain.

Bbecause i need points 

It’s b each orbits at a slower rate than the rate rate which the moon orbits the earth

Parents and friends
to have trust
to be comfortable with that person

Which of the following is an example of an opposing signal? no examplthates given.   i would say, that traffic lights in a city at major intersections direct the flow of traffic in opposite directions so would be an example.also, stop signs on either side of the same street would be an example. at a train crossing, the light for allowing car traffic in opposite directions or not would be another example.