In order to be used as a primary key, which of these characteristics must an attribute possess with respect to a single instance of the entity? Select all that apply.

1. which of the following is a search engine? a) mozilla firefox b)internet explorer c)google d)safari 2. which of the following statements is true? a) all search engines will provide the same results when you enter the same query. b) all search engines use the same amount of advertisements. c) some search engines are also browsers. d) search engines often provide different results, even when you enter the same query.

To produce a starlight effect in her photograph, lina should choose the filter for her camera.

Which computer network component connects two different networks together and allows them to communicate? a is a node (or a device) that connects two different networks together and allows them to communicate.