A.300m B.350m C.400m D.450m
A.5km/h B.10km/h C.15km/h D.20km/h
A.(tz+30℃)~(tz-30℃) B.(tz+20℃)~(tz-20℃) C.(tz+15℃)~(tz-15℃) D.(tz+10℃)~(tz-10℃)