Ascientist read about an experiment done by someone else. she does the same experiment in her lab to make sure it works.
this is an example of

The correct answer will be- repetition of the experiment to test the hypothesis

Explanation:

A scientific experiment is performed to test the hypothesis which checks whether the hypothesis is true or not true.

Testing the hypothesis is the key of the scientific investigation so the repetition of the experiments is done to check the validity of the hypothesis either by the same researcher who formulated the hypothesis or another researcher who check and verify the results.

Thus, the repetition of the experiment to test the hypothesis is the correct answer.

b. acid is the correct answer @jayxboof all social media

acid : acids are those which accepts an electron-pairs.

base : bases are those which donates ab electron-pairs.

alkali : it is a base that dissolves in water. it is basically a base and the ph greater than 7.

hydroxide ion : it is a poly-atomic ion which is negatively charged.