实验测得石灰石中CaO含量为27.50%，若真实值为27.30%，则（27.50%-27.30%）×100%/27.30%=0.73%为（）

A.43.59

B.43.60

C.43.61

A.≥50

B.≥43

C.≥45

D.≥52

A.91

B.92

C.93

D.94

A.真值为40mm，测得值为40.05mm

B.真值为40mm，测得值为40.02mm

C.真值为100mm，测得值为100.03mm

D.真值为100mm，测得值为99.5mm

A.≥49.0%

B.≥49.5%

C.≥50.0%

D.≥52.0%

A.CaO越高越好

B.SiO2含量越高越好

C.S含量越高越好

D.AL2O3含量越高越好

A.-0.1%;

B.+0.06%;

C.+0.1%;

D.+0.06%;