舵轴,舵销及舵承的磨损腐蚀情况的全面检查应在()。
A、船舶小修时进行
B、船舶检修时进行
C、事故修理时进行
D、船舶坞内检验修理时进行
采用比例,微分,积分控制的自动舵()。 ①能加快给舵速度; ②能自动消除单侧偏航角; ③结构简单,造价低; ④是比较完善的自动舵。
A、①~③
B、②③④
C、①③④
D、①②④
能产生黄曲霉毒素的霉菌是()
A、寄生曲霉
B、构巢曲霉
C、杂色曲霉
D、黑曲霉
E、以上都不是
成人体内水分含量约占体重的( )。
A、80%
B、75%
C、60%
D、90%
在曲线地段,横断面方向是与线路施测点的切线相垂直的方向。
A、对
B、错
You are using Oracle Database 10g. You performed an incomplete recovery of your database and opened the database with the RESETLOGS option. What is the effect of opening the database with the RESETLOGS option?()
AThis operation resets the SCN for the database.
BThis operation creates a new incarnation of the database.
CThis operation moves all the redo log files to a different location.
DThis operation deletes the old redo log files and creates new redo log files.
EThis operation updates all current datafiles and online redo logs and all subsequent archived redo logs with a new RESETLOGS SCN and time stamp.