Choose the correct verb form.

How long have you known / have you been knowing her sister?
The children have watched / have been watching cartoons for three hours.
A boy has been eating / has eaten sweets all evening, so he feels sick now.
He has seen / has been seeing that series about five times!
Michael has prepared / has been preparing for tomorrow’s test for hours, but he still doesn’t remember anything at all.
The bus has just arrived / has just been arriving, so you might catch it.