ask LSAT-3-4-9 again,many thanks

9. A scientific theory is a good theory if it satisfies two requirements, It must accurately describe a large class of observations in terms of a model that is simple enough to contain only a few elements, and it must make definite predictions about the results of future observations, For example, Aristotle’s cosmological theory, which claimed that everything was made out of four elements---earth, air, fire, and water---satisfied the first requirement, but it did not make any definite, Thus, Aristotle’s cosmological theory was not a good theory.

但这又不能说明Prediction about the results of future observations must be made by any good scientific theory

Prediction about the results of future observations must be made by any good scientific theory--->prediction is the necessary condition for good theory.

As it is in the argument, the absence of either A aor B, C cannot be established. So, A and B are the neccesary condition for C.

A, simple model     B, prediction,     C, good theory.

Maybe not right:

For example:

People can maitain self-respect only by continually earning the respect of others they esteem.  maintian...--->earning......

only  and must have the same function,so I think  :  

B, prediction,     C, good theory,

B--->C

这道问题已被老师改成了“could be"

In this argument,  only good theory can satisfy two requirements. So, if we get the requirments fulfilled, we must land on a good theory.  As for what about bad theory or no bad no good theory, nothing has been known. Therefore, dont streach outside the argument, just focus on what it said.  See the question" if all the statements in the passage are ture..."