单项选择题
If the tension elastic modulus of the beam with rectangular section is greater than the compression elastic modulus, the neutral axis of the section is () when the beam is in pure bending.()
A、Abovethe z-axis.
B、Onthe z axis.
C、Underthe z-axis
D、Non-existent
If the tension elastic modulus of the beam with rectangular section is greater than the compression elastic modulus, the neutral axis of the section is () when the beam is in pure bending.()
A、Abovethe z-axis.
B、Onthe z axis.
C、Underthe z-axis
D、Non-existent
A. 
B. 
C. 
D. 