34. Grid lines are shown at 1-unit intervals in the standard（x,y) coordinate plane below. Some of the 1-by-1 squares are shaded in the grid. What is the least number of additional 1-by-1 squares that must be shaded so the total shaded region will be symmetric about the y-axis ?

Answer and Explanation

Your Answer is

Correct Answer is H

Explanation

Take the side with more left and right sides of the y-axis in each row of grids and fill the other side. Then from top to bottom, each row needs to add 1+1+1+2+1+1, a total of 7 squares. Therefore choose H.