As president of the Senate in the 1830s, Martin Van Buren kept a gun near him to maintain order.

Choose the correct antecedent for the underlined pronoun.

even though there may be variations in human emotions over time, the poem “ a contribution to statistics” by wislawa symborska suggests that the only unchangeable characteristic is mortality.

the author poses a distinction between the approximate and non-approximate numbers which correspond to our need for certainty in life and the difficulty of achieving it. our efforts to measure the exact often fail because the world is not always clearly structured .the poem seems to imply   that the only thing that is certain and has an exact number is death.  

it should be

hard work gives a person a sense of satisfaction; likewise, it to pay the bills.

so the punctuation is not correct.

i know its the art of writing?