单项选择题
A.10MPa B.5MPa C.1MPa D.0.5MPa
A.应变花 B.3~6mm标准单轴应变片 C.20~40mm标距单轴应变片 D.80~100mm标距单轴应变片
A.20~250kHz B.10~20kHz C.300kHz D.20~60kHz