Mesosphere is the correct answer :)
CONTENTS<span>PRINTCITE</span>
On January 5, 1957, in response to the increasingly tense situation in the Middle East, President Dwight Eisenhower (1890-1969) delivered a proposal to a joint session of the U.S. Congress calling for a new and more proactive American policy in the region. The Eisenhower Doctrine, as the proposal soon came to be known, established the Middle East as a Cold War (1945-91) battlefield
In the 1800s and early 1900s slavery was very common among people, almost everyone had slaves. Today slavery is outlawed and is illegal to have slaves.
The first alternative is correct.
Presidential elections are held between a Republican and a Democratic Party candidate.
The dispute concentrates on two distinct projects and the democratic game allows either of them to win, depending on the will of the voter. In fact, hardly a party stays in power for long. Normally, there is alternation between Democrats and Republicans.
For example, Obama was from the Democratic Party. Now it's Trump from the Republican Party.
It protected Egypt from foreign invasions: the desert was practically impenetrable, which means that any possible invasion could only come from a place they could expect (and prepare for): the along the Nile or from the sea.
Knowing that they don't have to fear foreign invasions meant that Egyptians could focus on growth and culture.
