The well-trained [blank] follows the trail of the escaped suspect.
either dog or dogs

dog

Explanation: If it were "dogs" then there would be no "s" at the end of "follows".

The answer is "Dog" is the sentence is talking about a singular dog

the choice that is not a technique that you should use to come up with ideas for the topic of a research project is, writing about academic subjects that are not interesting to you. this does not belong to the techniques to come up with ideas because having no interest in a certain topic will lose your drive to come up with better ideas. it gives no room for improvement and acquiring of new ideas and information. 

explanation:

the correct answer is:   [c]:

                    →     " leave it out. "  

hope this is to you!

        best wishes!