Student absences

This task is about looking closely at a graph.
At Redhills College they counted the number of students who were absent each day. Here are the results for the first ten days of the term. 

Day number 1 2 3 4 5 6 7 8 9 10
Number of students absent 5 0 5 15 25 20 35 35 40 45
 These results were plotted on the graph below:

Question 2Change answer

List three things that are missing or incorrect about this graph.
1.  
2.  
3.