Why is biodiversity so important to ecosystems?

In a cellular network each cell is controlled by a tower what are these towers called?

You are almost finished updating a web site. as part of the update, you have converted all pages from html 4.0 to html5. the project is currently on schedule. however, your project manager has been asked by the marketing team manager to justify a day of time spent validating the site's html5 pages. the marketing team manager does not have technical knowledge of the internet or the web. which is the most appropriate explanation to provide to the marketing team manager?

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.