GAO report said hundreds of planes flying commercially today could be vulnerable to having their on board computers hacked.
Answer:
It starts as rain and freezes in the air.
Explanation:
Sleet is that form of precipitation that freezes down in air or after the contact with the earth due to extreme low temperature in a region. For example, sleet is common in Tundra region like Alaska and Northern Canada.
Not sure if you still need it but the answer is (c) new cities were built along the shores of the Great Lakes.
The answer is making maps
I think the answer will be option a