The answer to that question is them. The class is a collective noun for a bunch of students that are learning from a teacher. Since we are referring to people, then we cannot use it because the noun it is used for inanimate objects. Pronouns like them are used to refer to people
The word candles is plural.
correctly
speak it out loud, if it sounds weird, it's wrong.
It is a simile. A simile is comparing two things with like or as. Example: "They were as quiet as a mouse". Now never confuse this with a metaphor which doesn't use like or as, but still compares two things. Example: "She is a walking encyclopedia" . This is telling you indirectly that she is a very smart and talkative person. A simile would tell you directly
Sadness. Negative suffix is a suffix that attaches a negative meaning to the word or word-stem preceding it.
