PROBLEM 3.1: For each of the following, make up an R expression that uses an object named fireplace. The expression should have enough context to be able to identify the name as belonging to 1. a data table 2. a function 3. the name of a named argument 4. a variable PROBLEM 3.1: For each of the following, make up an R expression that uses an object named fireplace. The expression should have enough context to be able to identify the name as belonging to 1. a data table 2. a function 3. the name of a named argument 4. a variable