Question

1. read the following statement. one part of the water treatment process acts as a barrier that blocks out unwanted particles. which detail from the article provides the best support for the above statement? (a) the steps of water treatment the first step is usually to add coagulants. these are chemicals that cause those solid bits to clump together. (b) by making these bits clump, they become bigger — and easier to remove. a gentle shaking or spinning of the water — called flocculation — helps those clumps to form (1). (c) next, the water flows into big tanks where it will sit for a while. during this settling period, the solid sediments begin to fall to the bottom (2). (d) the cleaner water atop it then moves through membranes. like a sieve, they filter out smaller contaminants (3).

Explanation:

The statement mentions a part of water - treatment acting as a barrier to block out unwanted particles. Option D describes membranes in the water - treatment process that act like a sieve to filter out smaller contaminants, which is consistent with the idea of a barrier blocking out particles. Options A, B, and C describe other steps in water - treatment (coagulation, flocculation, and sedimentation) that do not act as a barrier to block out particles in the same way.

Answer:

D. The cleaner water atop it then moves through membranes. Like a sieve, they filter out smaller contaminants (3).