In what section of the paragraph does the writer have the most positive attitude?Of all the jobs I have held so far, serving as a summer intern in...

To reinforce what has been pointed out, the
topic sentence is always the one to contain the most important idea of a
paragraph.  As such, the main idea of the student's
internship is stated:  working as a summer intern in a congressman's office; and,
the opinion follows: it has been the most gratifying.  The
topic sentence also sets the tone of the paragraph.

The
next sentence is the first supporting sentence which reinforces the
positive tone of the topic sentence:  the student gained
some important insights.

After this sentence, which is
equally as positive as the topic sentence, the others that follow act as supporting
sentences by providing examples of the negative experiences
that the students have had with other jobs, thus reinforcing by contrast
why the summer intern job was his/her "most
gratifying."  So, the negative serves to emphasize the positive tone of
the beginning of the paragraph.