Answer:
Fn = Shelf
Explanation:
The shelf is pushing the book upwards.
The force of gravity affects all objects on Earth by pulling them towards the centre. The Earth is close to spherical in shape as this is the geometry gravity prefers. Without gravity, objects would be floating in space. The atmosphere would not exist as the air particles would have no force pulling them towards the planet. Gravity means when you throw something up, most of the time it will come down. It is a force, which causes objects to accelerate when they fall.
Answer:
B.
Explanation:
They take up the host organelles to reproduce more viruses inside.
The answer is (b.) ATP and calcium
ATP (Adenosine triphosphate) and Calcium participates in the muscle movement. In a muscle contraction, Calcium ions are released to initiate upon the depolarization of the membrane which is induced by nerve impulses. While the ATP is required to the shortening of actin and myosin filament crossbridges.
Je ne peux pas vraiment expliquer la réponse en raison de votre question confuse, mais voici une note pour faire des questions non confuses la prochaine fois
