A.24h后,鋸末養(yǎng)護4~5d B.24h后,鋸末養(yǎng)護2~3d C.12h后,鋸末養(yǎng)護4~5d D.12h后,鋸末養(yǎng)護2~3d
A.宜做成縱向的 B.宜做成橫向的 C.宜做成90o角 D.宜做成45o角
A.3m B.4m C.5m D.10m