The correct answer here is "cell membrane". Generally it makes sure that nothing enters or leaves the cell, except by its highly guarded "gates", such as ion channels, that let some particles through - but they're very picky about whom to let in!
The answer is B and that is the same reason that everything stays on the Earth because it has very strong gravity.
Your nose and your mouth are both a portal of entry into your body. If you cover one and not the other it defeats the purpose because Bacteria can still enter the system. They are both part of your respiratory system.
Answer:
2400 Joules
Explanation:
Work done = force × distance
work done= 600×4
Therefore, work done=2400joules
P.S: the SI unit for work done is JOULES
PLEASE MARK AS BRAINLIEST
Answer:
D
Explanation:
Carbo (Carbon) Hydr (hydrogen) Ates (Oxygen)