B is the answer and I hopes this helps
Answer: To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight.
The intervertebral discs, which are between vertebrae, are the parts that prevent the vertebrae from grinding against one another.
The intervertebrals discs act as a cushion; they absorb the stress and shockw that occur during movement, preventing such grinding.
Answer: The carbon dioxide is the output and oxygen is the input of the Scuba apparatus.
Explanation:
The scuba apparatus is a life saving apparatus used by the sea divers. It recycles the exhaled gas and removes the carbon dioxide and compensates for the utilized oxygen gas before the diver is actually supplied with the gas for the purpose of breathing in a circuit. Hence, the carbon dioxide gas is the output and the oxygen is the input.
Yes, because the envelope can be a important document- so therefore it can be considered "confidential".