There are two ways to tell if the timing belt has been replaced. One is obvious-you are looking at a service receipt showing the replacement.
Swimlane diagrams are used whenever you need to show activities, tasks, or process steps which are being performed by different actors/roles. You can use swimlanes to group activities in an activity diagram or process flow by any category what you need: by role, by system, by department, etc.
The Clove Hitch is used to secure the boat to a piling. Wrap the line around the piling and bring the end back around and over the standing line. Pass the line around the piling again on the opposite side. Slip the end under the line as shown.