The amount of test cycles required to find out the fatigue stress of hard aluminium alloys is ____________

The amount of test cycles required to find out the fatigue stress of

1.	The amount of test cycles required to find out the fatigue stress of hard aluminium alloys is ____________
A.	64,000,900,000
B.	500,000,000
C.	3000
D.	27
Answer» C. 3000