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.
Answer:
Colloids or colloidal solutions are mixtures in which microscopically dispersed insoluble particles of one substance are suspended in another substance. The size of the suspended particles in a colloid can range from 1 to 1000 nanometers (10-9 meters).
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Answer:
Plants perform photosynthesis to produce glucose.
Explanation:
Glucose is used by plants for energy and to make other substances like cellulose and starch.
The answer is d. Food chain
