Is revolution necessary in bring about political change

Yes, revolution is necessary in bringing about political change because it also brings social and economic changes which have the power to influence political change.

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering

richard milhous nixon (january 9, 1913 – april 22, 1994) was the 37th president of the united states, serving from 1969 to 1974, when he became the only president to resign (quit). he is also known for corruption and the watergate scandal which resulted in the public losing trust in him and his resignation.