The above figures show the force required to move a 100 g object over different surfaces. The friction is greatest at _______.
A Surface W
B Surface X
C Surface Y
D Surface Z
This question is very hard for 3rd standard!you don't know how to make questions at all!!!!!ððððð¡ð¡ð¡ð¡ð¡ð¡ð¡ð¿ð¿ð¹ð¹ðð