A transitional topic sentence is most often implied, although of course it should be noted that this is not always the case, and that it varies greatly with the speaker.
Why would you do something like that to yourself.
You reciprocate when you return a favor, return a compliment, or respond "the same to you" to the angry guy in the car you just passed. In short, you react to an action, statement, or emotion by mirroring it. This one comes from the Latin verb reciprocare, meaning to move back and forth.
By how well he or she does the job
