What is the Oder if events in which things happen?

Which three sentences in this excerpt from arthur conan doyle's "the contest" suggest that the author's tone is mocking?

The greatest gift the sumerians gave the world was the invention of writing. the sumerians were wealthy people. they needed some way to keep track of what they owned. they began drawing pictures. they used a reed as a pen. they drew on soft pieces of clay. the soft clay was then dried in the sun. the tablet became a permanent record. later, the sumerian drawings changed into wedge-shaped symbols. this kind of writing is called cuneiform. by putting symbols together, the sumerians could write entire sentences.

Similarities between speaker’s delivery and active listening?