Unliftable Knowledge

Exploration Stage: Post Office
From: Kira Woodville
Description: It's said in the newspaper that the scientist came to the City with a large suitcase: "It was very heavy for others due to the weight of knowledge that was stored in it." Hmm, it would've been more useful to know the size or material the suitcase was made of, or any distinctive features. All right, I'll figure it out myself. Do you think it may be one of those suitcases? Let's check!
Completed: Wow, it's such a heavy thing! Help me out! The inventor's suitcase is absolutely unliftable! Let's look at its contents and put everything in order so that it'll be easier for me to organize later.