【单选题】Before a Flashback Table operation, you execute the following command: ALTER TABLE employees ENABLE ROW MOVEMENT; Why would you need this to be executed?()
A.
Because row IDs may change during the flashback operation
B.
Because the object number changes after the flashback operation
C.
Because the rows are retrieved from the recycle bin during the flashback operation
D.
Because the table is moved forward and back to a temporary during the flashback operation
【单选题】Before a Flashback Table operation, you execute the following command: ALTER TABLE employees ENABLE ROW MOVEMENT; Why would you need this to be executed?()
A.
Because row IDs may change during the flashback operation
B.
Because the object number changes after the flashback operation
C.
Because the rows are retrieved from the recycle bin during the flashback operation
D.
Because the table is moved forward and back to a temporary during the flashback opertion
【单选题】有关放射性标记物的放射化学纯度的描述,正确的是 ( )
A.
是指结合于抗原上的放射强度占总放射强度的百分率
C.
是指标记抗原结合于抗体的放射强度占总放射强度的百分率
D.
放射化学纯度测定方法是加10倍量抗体和标记抗原反应,测算出B/(B+F)百分率
E.
标记后放射性标记物的分离纯化程度不影响其放射化学纯度
【多选题】以下关于卖出看涨期权的说法不正确的有( )。
C.
期权被要求履约风险=执行价格+标的物平仓买入价格-权利金
【单选题】Would you find out how many parts you need to design a well-structured answer to why should I hire you?
【简答题】用K 2 Cr 2 O 7 法测定Fe 2+ 含量的实验中,加入H 3 PO 4 的目的是______,______。
【单选题】描述放射性标记化合物的放射性活度占该样品的总放射性活度的百分比的单位是