The sentence ends with a string of "wh-" noun clauses. These clauses are usually not queries, so the last 1 must also not be an issue. "Which one would be the best" is clearly a question structure, so it is sensible that " Sometimes, taking part in a cleaning method, https://share.evernote.com/note/a8fd1cb2-5733-5366-f5df-7a36578ae666