Excerpt 1. Scientific data: it presents information <em>related to science.</em>
Excerpt 2. Expert opinion: it´s an opinion of a person with <em>high level of</em> <em>knowledge</em>. "Accordint to <em>Morten Olsen</em>, chair of a recent <em>Artic assessment</em> on 2-Artic snow and ice-conditions"
Excerpt 3. Association: a feeling that <em>relates</em> to something. <em>"like a cruising jet"</em>
Excerpt 4. Emotional appeal: a way that uses the <em>emotions</em> to convince the audience. <em>"...the melodious songs of these beautiful birds might be silenced forever."</em>
