“The Gobi Desert is dangerous and dry. There is a little water, but is rare, and an oasis is very rare. The Taklamakan Desert, China's other desert, is the second largest desert in the world. ... Crossing the Taklamakan is dangerous and can be deadly.” (china.mrdonn.org)
Answer:
Because the earth's axis is tilted. ... During the summer, the sun's rays hit the Earth at a steep angle. The light does not spread out as much, thus increasing the amount of energy hitting any given spot. Also, the long daylight hours allow the Earth plenty of time to reach warm temperatures.
To clear things up a bit, when the Kushites became allies with the Hyksos, it was during the Hyksos' reign over Egypt, and the Kushites were independent, NOT during the invasion.
Kushites were afraid that the Egyptians would enslave them again, but they did not know the Egyptians would rise to power again, and the Kushites were encouraged to learn the Egyptian way. Hope this helps.