Answer: Layer a is 500 million years old.
Explanation:
Trilobite is a member of the group of extinct arthropods found as fossils and they can be identified by the three-lobed as well as three segmented forms. These were the marine animals. These were appeared initially in the Cambrian Period. They used to live 542 million years ago so the fossils can be estimated to be aged of 500 above years old. These animals used to dominate in the sea area.
Adler and Adler are currently testing what hypothesis that: Self-injury is a subconscious response to childhood trauma; option C.
<h3>What is a hypothesis?</h3>
A hypothesis is an explanation put forward to test an observation without prior testing of the observation.
A hypothesis is like a guess based in observation alone.
Adler and Adler hypothesis on self-harm was that self-injury is a strategy used to manage unbearable emotional pain.
In conclusion, a hypothesis is tested to prove or disprove it.
Learn more about hypothesis at: brainly.com/question/606806
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Not all substances are soluble an example would be sand
The correct answer is A. Vascular tissue
Explanation:
The vascular tissue refers to different cell types that form conduction structures in vascular plants and whose main function is to transport substances such as nutrients, water, and minerals that support functions in the plant including photosynthesis. The two main structures that are part of this are the xylem that transports from elements from the roots to the leaves and the phloem that transport substances from leaves to the roots. Additionally, the xylem is composed of cells called tracheids, vessel elements and the phloem is composed of sieve-tube cells and companion cells. Therefore, tracheids, vessel elements, etc are components of the Vascular tissue.