He's never told a lie. - He has never told a lie.
He's never told a lie.
He has never told a lie.
He's been teaching for 20 years. - He has been teaching for 20 years.
He's been teaching for 20 years.
He has been teaching for 20 years.
... has an opportunity for someone to design systems that go in ...
... lt has taken 200,000 years of human history, ...