Why did agriculture, which was previously resisted violently, finally prevail among the pastoral nomads as a way of life

A．Robert survived the plane crash.
B．All the passengers were killed in the plane crash.
C．Robert was killed in the air crash.
D．Robert is a wonder-working person.

A．He feels rushed.
B．He hates to pack.
C．He doesn’t like to restrict his diet.
D．He’s worried about his lecture.