Suggest a design for a notification mailbox service that is intended to store notifications on behalf of multiple subscribers, allowing subscribers to specify when they require notifications to be delivered. Explain how subscribers that are not always active can make use of the service you describe. How will the service deal with subscribers that crash while they have delivery turned on

What must you do before formatting a paragraph?

In a response of approximately 50 words, explain why it would be essential for the successful a/v technician to participate in additional coursework, presentations and seminars offered by equipment manufacturers as well as annual conferences attended by colleagues in the industry.

Why were most movies from the late 1890s until the early 1930s only filmed in black and white? there were only a few people who could afford the technology to produce color motion pictures back then. audiences did not want color motion pictures until later. the film used to make color motion pictures often overheated, which was a safety hazard, so it was generally not allowed. color films had to be hand-colored, frame by frame.