Pan Arabism is a political movement promoting the idea in which Arabs should unite in forming one country or a state. The idea was first done during 1800s in the later part and 1900s.If this stayed it would have led to greater unity for Arab and countries like Egypt and Syria could have stayed united which is the answer.
Dark Matter only: detected through its gravitational attraction, has mass, most common form of mass in the halo of the Milky Way Galaxy, likely to consist of subatomic particles
Dark Energy only: inferred to exist from the measured acceleration of the universe's expansion, the proposed source of a universal repulsive force
BOTH: the universe contains more of this than it contains matter made from atoms, we do not know what it is made of
NEITHER: blocks light from stars behind it, "dark" because it emits only infrared light
The entire United States and the rest of the world serve as the hinterland for all of the following cities except Tucson.