Cannot is formal, while can't in informal.
"Cannot" and "can not" are interchangeable, but when you are asking question for example:
"why can't I...", you can also say "why can I not..." (which is more formal), but you can't say "why cannot I..."
Answer:
It leads Anne to doubt whether Mr. Dussel is prepared for living in the annex is in the first day of Dussel in the Annex he immediately asked Anne all sorts of questions.
Explanation:
Check your books :)
