To prevent blood flowing back after each heartbeat. They ensure that the blood flows only in one direction (back to the heart).
This answer is best suited to say that the Broca's area is responsible for speech production and function. Moreover, comprehension is done in the Wernick's area. Thank you for your question. Please don't hesitate to ask in Brainly your queries.
Answer:
At the bottom of the sequence
Explanation:
According to the "principle of superposition of strata", the oldest rocks are formed at the bottom of sedimentary rock sequences.
The oldest rock layer would contain the the oldest fossil. Weathering, erosion, transportation and deposition would bring all sediments which includes rock materials and remains of living organisms to the basin where they would be lithified to form sedimentary rocks. This makes the oldest fossil to be at the bottom of the sequence. As time progresses, the fossil sequence would continue to accumulate and young upwards as the strata becomes relatively younger. Also, we know that fossils succeed one another in a definite manner.
This why relative dating of rocks can be possible.
