答案:交替
A. (A)225
B. (B)250
C. (C)275
D. (D)200
A. (A)0.5~1.0m
B. (B)1.0~1.5m
C. (C)1.0~2.0m
D. (D)1.5~3.0m
A. (A)0.25m
B. (B)0.5m
C. (C)0.75m
D. (D)1m
A. (A)500m
B. (B)1000m
C. (C)300m
D. (D)1500m