Answer:
The climate of the earth throughout history has always been <em><u>fluctuated between hot and cold periods. </u></em>
Answer:
<h3>Our universe may live in one bubble that is sitting in a network of bubble universes in space. ... The concept is known as a "parallel universe," and is a facet of the astronomical theory of the multiverse. The idea is pervasive in comic books, video games, television and movies.</h3>
Answer:
The direction of the B-field is in the +y-direction.
Explanation:
The corresponding formula is

This means, we should use right-hand rule.
Our index finger is pointed towards +x-direction (direction of velocity),
our middle finger should point towards the direction of the B-field,
and our thumb should point towards the +z-direction (direction of the force).
Since our middle finger in this situation points towards +y-direction, the B-field should be in +y-direction.

Answer:
mass.
Explanation:
other physical factors are changeable but the mass of a particular substance is always constant.
Answer:
B. posititvely charged particles
Explanation:
Opposites attract to each other, and the same charge repels.