Combine each pair of sentences below so that one sentence is added to the beginning of the other in order to state a fact or answer a question.Who...

From your question, I think what you are after is a way of
combining the two sentences that would answer the question of how is the ventriloquist
giving voice to the dummy that is in his hand. Looking at the sentences, we can easily
do this if we make them into one statement and placing the first sentence towards the
beginning of the new structure. Therefore, if we apply this, we will come up with the
following statement:

To discover the secret of how the
ventriloquist manages to throw his voice, you need to watch the ventriloquist very
carefully.

This melds the two sentences together, creating
one sole sentence that is used to state a fact but also to answer the implied question
regarding the ventriloquist's skill in throwing his voice.