In his experiment on spontaneous generation, louis pasteur changed only one thing between his experimental groups: whether or not the neck of the flask was broken. that means that his experiment was

The correct answer to this open question is the following.

In his experiment on spontaneous generation, Louis Pasteur changed only one thing between his experimental groups: whether or not the neck of the flask was broken. That means that his experiment was controlled.

When scientists do control experimentation, this means that the scientist can manipulate directly the experiment. The aim is to test just one variable at the time to find specific results. The correct name for the variable being tested is the "independent variable." This allows the scientist to adjust the effects or minimize the effects of the subject matter. That is what Louis Pasteur did in his experiment.

c.) the country needed a stronger central government.

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.