How had the use of social media changed people writing

What is the meaning of the word checking as it is used in this sentence from the second paragraph of the passage?

"dogs make wonderful pets because they us stay happy and healthy"the topic sentence is "dogs make wonderful pets" i need writing a sentence that is unrelated to the topic and can be eliminated.

Read the passage below and answer the question that follows. ‘you make me feel uncivilized, daisy,’ i confessed on my second glass of corky but rather impressive claret. ‘can’t you talk about crops or something? ’ i meant nothing in particular by this remark but it was taken up in an unexpected way. ‘civilization’s going to pieces,’ broke out tom violently. ‘i’ve gotten to be a terrible pessimist about things. have you read ‘the rise of the coloured empires’ by this man goddard? ’ ‘why, no,’ i answered, rather surprised by his tone. ‘well, it’s a fine book, and everybody ought to read it. the idea is if we don’t look out the white race will be—will be utterly submerged. it’s all scientific stuff; it’s been proved.’ in this passage, tom’s ideas about race relations come off as uncivilized. what literary device is fitzgerald using here? irony personification metaphor simile