In the first phase of the Industrial Revolution, machines were invented whose main advantage was that they worked faster than human workers.
Examples
In the first phase of the Industrial Revolution, machines that worked faster than human workers were invented.
Causal (because) Economically attractive, since many unskilled workers could be replaced by a few skilled ones >> the technology became widely used
Today managers seek technology that lets them replace highly paid skilled workers with fewer, less-skilled workers.
Evaluate
Two examples from two eras, and the stem asks what proposition they illustrate together. Look for what they share. In the first, employers adopted machines because they could swap many unskilled workers for a few skilled ones, which was cheaper. In the second, employers want technology that swaps expensive skilled workers for cheaper, less-skilled ones. The direction of the swap reverses, from unskilled-to-skilled to skilled-to-unskilled, so the point cannot be about skill levels as such. What stays constant is the motive: in both cases the technology is attractive because it cuts what the employer pays for labor.
Nothing in the examples says what workers should do, whether skilled workers have lost their edge, or how many jobs technology creates. The examples are about why employers reach for new technology.
Goal
Find the proposition about employers' motive for adopting technology, that it lowers their labor costs. Propositions about workers' prospects or about job creation are not what the two examples have in common.