The attraction that holds two covalently bonded atoms together is called covalent bond
Simple....
as you've learned... cells create tissue..tissue creates organs...organs create organ systems..and organ systems create organisms. They all work together to create something...
An example:
muscle cell-->>muscle tissue-->>heart-->>circulatory system-->>the circulatory system makes up a part of the body.
Thus, your answer.
Because they are made to perform two different functions. Cells are part of tissues that are part of organs that perform a certain function. For example, your bone cells are made to make blood cells, so they wouldn’t be in your lungs as well.
Rain is the correct awnser