Question

because the air pressure under the roof is high while the air pressure above the roof is low. And the air always blow from high pressure to low pressure.

Answer 1

Whenever there are high winds, such as in storms, thin metal roofs on sheds as well as concave roofs on huts are sometimes blown away.

One explanation provided to me said that the higher velocity of the air outside causes the air pressure above the roof to decrease and when it has decreased to a certain extent such that the air pressure above the roof is lesser than the air pressure beneath the roof and due to some kind of osmosis, the air particles move from the area of higher pressure (beneath the roof) to the area of low pressure. In this process, the roof is blown away.

Answer 2

The Early Nationalists,[3] also known as the Moderates,[4] were a group of political leadersin India active between 1885 and 1905. Their emergence marked the beginning of the organised national movement in India.[5] With members of the group drawn from educated middle-class professionals including lawyers, teachers and government officials, many of them were educated in England. They have become known as "Early Nationalists" because they believed in demanding reforms while adopting constitutional and peaceful means to achieve their aims.[6][7] The Early Nationalists had full faith in the British sense of justice, fair play, honesty, and integrity while they believed that British rule was a boon for India.[8] The Early Nationalists were staunch believers in open-minded and moderate politics.[9][10]