The inner core is solid because it is made of very dense, or heavy, materials like iron and nickel. Even though it is very hot, these materials don't
She does work from the moment she touches the book until she lets it go. Work is anything that requires energy. Therefore, she is working as she picks up the book, carries it, and when she is lifting it onto the shelf.
<span>In science, </span>observation<span> can also involve the recording of data via the use of scientific instruments. The term may also refer to any data collected during the scientific activity.
Hope this helps,
kwrob</span>