HI.dzung1991
Beside motivator, general background should be given in the introduction.
However, ah_zafari said that the opinion should be stated in the conclusion in this type of essay.
AND.
Firstly, almost most (be careful with the use of most, almost and mostly) famers can produce crops that grow bigger and faster as well as modifying modified crops to be more resistant to disease or insects.
should be 'famers can produce crops that grow bigger and faster as well as
modifyingmodify crops to be more resistant to disease or insects.'
because famers can produce...as well as (can) modify... is more parallel.:-)