Answer:
D fossil record
Explanation:
Depending on what layer of earth the fossil was recorded then they could determine a rough date. Then they would use carbon dating to be more exact.
I think its A) A antigens
C Diagram the flow of oxygen-rich blood through the body of a non-smoker. Then diagram the flow of blood with less oxygen (from airway resistance) through the body of a smoker.
<u>Answer</u> : option A gateway drug
<u>Explanation</u>:
- A gateway drug is considered to be a type of habit forming drug which itself may not be addictive in nature but their use may lead to the person getting addicted to other drugs.
- The increase in probability of using other illegal drugs when a person is using a gateway drug is because of the alteration in the brain which leads to an inclination towards drug usage and a carefree behavior.
- Besides alcohol, marijuana and tobacco are also considered to be gateway drugs.
- It has been shown that the use of alcohol acts a gateway for many drugs such as cocaine.
- The gateway drug theory has stated if any of the gateway drugs or a mixture of them is introduced into a life of a teenager then it leads to an increased chances of experimentation with other drugs in the future.
- Since, alcohol is linked to an increased probability of using illegal drugs in the future, it is considered to be a gateway drug.
The absolute threshold for human vision is the ability to see a candle from 30 miles away on a dark night
