Ben is taking a typing class, and the following line graph represents the number of words per minute he was able to type each week. According to the graph, how many more words per mioute could Ben type in week four than in week 2? A. 20

B. 15

C. 10

D. 5​

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?