The remains of the pharaoh are intact, and the wrappings of the mummy contain clues about his life.
We need to use "are" instead of "is" is because the verb to be is referring to the remains. Therefore, it needs to be a plural verb to go with the noun. Likewise, we need to use contain instead of contain because it referrs to wrappings. In the present tense, we only add -s to the verb if we are talking about he, she, or it.