A.∣δ∣≤0.05 B.∣δ∣≤0.01 C.0.05<∣δ∣≤0.1 D.0.1<∣δ∣≤0.2
A.∣δqv∣≤0.025 B.∣δqv∣≤0.05 C.∣δqv∣≤0.1 D.∣δqv∣≤0.2
A.20-5 B.20 C.20+5 D.20±5