We know when you look at something from the back, you may see a different look, plus, the left and right sides flip, as shown in this example:
Now, keep in mind, the back view may or may not look different but left and right are always flipped in the back view. Try:
Sometimes, you have to flip and flip again. Notice if you flip up and down, the left and right sides would NOT change.
1）C
2) E
3) C
4) E
5)E
6) B
#1=E
#2=C
#3=E