The correct answer option is C. textbook.
An online textbook or e-book is a digitally readable version of a physical textbook which is meant to be read on some digital device, for instance PC's. laptops,tablets, mobile phones, etc.
E-books, like physical textbooks, include text, images or both but require a digital medium to become readable. However, it is considered a drawback since to use an e-book, the user is dependable on the availability of some digital device.
The medulla oblongata detects the levels of oxygen and carbon dioxide concentrations and signals the muscles in the heart, the lungs and diaphragm to increase or decrease thebreathing. The pons controls the speed of inhalation and exhalation orrespiration rate depending on the need of the body.
Answer: We can tell how life existed on earth and how different plants and animals are related to each other. Often we can work out how and how and where they lived, and use this information to find out about ancient environments. Fossils can tell us about the past.
Explanation
Answer:
dehydration synthesis; lipid c.
Explanation:

<em><u>Nitrogen</u></em><em><u> </u></em><em><u>is</u></em><em><u> </u></em><em><u>not</u></em><em><u> </u></em><em><u>a</u></em><em><u> </u></em><em><u>product</u></em><em><u> </u></em><em><u>of</u></em><em><u> </u></em><em><u>photosynthesis</u></em>