If a scientific experiment repeatedly gives the same results, the experiment is

The correct answer will be-considered reliable and valid experiment.

Explanation:

A scientific method involves various steps which help understand and answer the natural phenomenon.  

One of the steps includes the proposal of the predictive hypothesis which could be tested through the experiment. The experiments are performed on the basis of which the hypothesis could be disproved or proved.

If the experiment is performed several times by the same fellow or other fellows and experiment provide the same result, this will indicate that the experiment is reliable and the methodology will be considered valid.

Thus, considered a reliable and valid experiment is the correct answer.

answer; both surfaces of the membrane are nonpermeable