选择题
2008 AMC 8 Problem 11: Dogs and Cats
Each of the 39 students in the eighth grade at Lincoln Middle School has one dog or one cat or both a dog and a cat. Twenty students have a dog and 26 students have a cat. How many students have both a dog and a cat?
A.
7
B.
13
C.
19
D.
39
E.
46