The past perfect refers to a time earlier than before now. It is used to make it clear that one event happened before another in the past. It does not matter which event is mentioned first - the tense makes it clear which one happened first.
According to researchers...
because that means scientists have researched it
Explanation:
When you open PowerPoint, you’ll see some built-in themes and templates. A theme is a slide design that contains matching colors, fonts, and special effects like shadows, reflections, and more.
On the File tab of the Ribbon, select New, and then choose a theme.
PowerPoint shows you a preview of the theme, with four color variations to choose from on the right side.
Click Create, or pick a color variation and then click Create.
Insert a new slide
On the Home tab, click the bottom half of New Slide, and pick a slide layout.
It is a synonym because it is a word that means the same thing