Answer:
A-
Tides are caused mainly by <u> </u> in how much the moon's gravity pulls on different parts of Earth.
The force of gravity pulls the moon and Earth toward each other.
The moon's gravity causes high tide on the side closest to the moon.
The moon's gravity pulls Earth, leaving water behind causing an additional high tide.
Low tides occur between the two high tides.
There are 2 low tides and 2 high tides a day.
B-
Their combined forces produce a tide with the greatest difference between consecutive high and low tides, called a spring tide.
Spring tides occur once a month, at new moon and at full moon.
During the moon's first-quarter and third- quarter phases, the line between the moon and the sun is at right angles to the line between Earth and the moon.
This produces a spring tide, a tide with the greatest difference between consecutive low and high These occur twice a month.
(sorry I didn't really understand the first one)