each. In each case, identify the entities involved and how they are interacting [upload a scanned copy of your drawing or a photo]. (a) A patient calls a doctor's office for an appointment and the desk clerk receives the call and asks for patient details and appointment date. The clerk then checks with the doctor calender's (by logging into a separate system, say "doctor's schedule") and checks whether the requested date is available. If so, she confirms the date to the patient and enters the same date into the doctor's calendar/schedule. (b) A client program connects to a remote system to get some Al services (say, facial recognition). The client program uploads a photo that has a set of human faces on it to an HTTP server and the server uploads the same photo to the "face recognition" server to get the faces in that photo to be detected and annotated (e.g., with name and gender). Since face recognition is a time-consuming operation and the server can take a varying amount of time to process (due to the server's current workload, and other factors), the HTTP server sends the same request to two face recognition servers and returns the result to the client whenever one of the two servers returns the result (which one is the earlier). The schematic looks like the following