it is B cells produce antibodies and T cells destroy infected cells
Water vapor , you need a liquid to have acid rain-(rain is water btw)
Angiosperms have ovaries; gymnosperms do not.
The Earth and Moon compare in terms of gravitational force as Earth's gravitational force is stronger than the Moon's.
Option A
<u>Explanation:</u>
According to universal law of gravity, the gravitational force is the attractive force between two objects separated by a distance. The magnitude of gravitational force is directly proportional to the product of masses of the objects and inversely proportional to the square of the distances between them.
In this case, the gravitational force acting on us due to Earth will be considered due to the mass of Earth as the mass of Earth is very large compared to our mass.

So as the mass of the Earth is greater than the mass of the moon, so the gravitational force of Earth will be stronger than that of Moon.