Descendant Selectors

Question

When you are using descendant selectors, it is necessary to have
both the id and class selectors in the paragraph , and then emphasize the selected text with the em?

Answer 1

AFAIK you can mix (aka combine) elements, id's and classes as selectors into a combination for reaching the descendants:
https://www.w3schools.com/css/css_syntax.asp
https://www.w3schools.com/css/css_combinators.asp

Answer 2

thanks Alvaro for answering

Answer 3

*keyboard