Direction: Each of the following items in this section consists of a sentence, the parts of which have been jumbled. These parts have been labeled. Given below each sentence are four sequences. You are required to rearrange the jumbled parts of the sentence and mark your response accordingly:

humans and machines have co-existed (P) / dating back to the invention of (Q) / the potter's wheel in ancient Mesopotamia (R) / at the physical level for millennia (S)

To form a meaningful sentence, we must identify the subject and connect the phrases logically:

• Part P ("humans and machines have co-existed") establishes the main subject and verb of the sentence.
• Part S ("at the physical level for millennia") logically follows Part P to describe the nature and duration of this co-existence.
• Part Q ("dating back to the invention of") introduces the origin of this timeline.
• Part R ("the potter's wheel in ancient Mesopotamia") completes Part Q by naming the specific invention.

Connecting them in the sequence P S Q R yields the grammatically correct and coherent sentence: "Humans and machines have co-existed at the physical level for millennia dating back to the invention of the potter's wheel in ancient Mesopotamia."