How is theme of loneliness developed in chapter 4? thinking about the characters lennie, crooks, candy, and curley's wife

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

Ineed badly ! i got to get this done and i can't get it done tomorrow! 1. expand the meaning of each sentence by adding adjectives. (dinner cooks.) (clown chuckled.) (car raced.) (dancer spun.) (panthers growled.) (leaves fall.) (bread baked.) (lake glistened.) (ship glides.) 2. using the sentences above, expand the meaning by adding adverbs. 3. using any five of the sentences from #2, expand the meaning by adding a compound word to each sentence. 4. using any three of the sentences from #3, expand the meaning by adding a prepositional phrase to each sentence. 5. using any one of the sentences from #4, expand the meaning by adding a synonym to this sentence.

According to the police officer, the car accident could not have been avoided.