Is the group of words a sentence or a run-on sentence?
the sand at the beach is hot it hurts to walk across it.
a. sentence
b. run-on

they insisted that there was not enough time to learn everything.  

explanation:

if they were going to steal the answers that is simply because they insisted that there was not enough time to learn everything.  

comfortable

explanation:

one type of the adjectives is predicate adjective. a predicate adjective is an adjective which follows a linking verb and modifies or refers back to the main subject of that linking verb.

it usually is used just before the noun it modies.

here in this example:

'penguins seem comfortable in the coolest habitats', comfortable is the predicate adjective which follows the linking verb 'seem' and modifies the noun.

b. the poet identifies with private people.

    in the stanza, dickinson states she doesn't wish to seek fame and recognition from the public eye. nor is she afraid of authority figures, and you can definitely tell she isn't hiding something. more as she identifies with private people, who are not known by the community