The first world war brought about an urgent need for

Question

Type of sentence? Compound, complex, simple, compound-complex?

1. The First World War brought about an urgent need for communications.
2. The primary research report is a professional report, which contains original research data.
3. The stability panel is an important preflight planning tool because the relative stability of an airmass is indicative of the type of clouds that can be found in a given area.