A、有两种比例,对于长试样L<sub>0sub>=8d<sub>0sub>,对于短试样L<sub>0sub>=5d<sub>0sub> B、有两种比例,对于长试样L<sub>0sub>=8d<sub>0sub>,对于短试样L<sub>0sub>=6d<sub>0sub> C、有两种比例,对于长试样L<sub>0sub>=10d<sub>0sub>,对于短试样L<sub>0sub>=6d<sub>0sub> D、有两种比例,对于长试样L<sub>0sub>=10d<sub>0sub>,对于短试样L<sub>0sub>=5d<sub>0sub>