机挂旋转式撒肥机
tractor-mounted spinner distributor
机引撒肥机
tractor-drawn fertilizer distributor
气动式撒肥机
pneumatic fertilizer distributor
振斗撒肥机
fertilizer distributor with oscillating spout
转盘式撒肥机
spinner fertilizer spreader
DDM安全机制
Distributed Database Discretionary and Mandatory
Oracle 10g安全机制
security mechanism of Oracle 10g