为自己加油

Which two are true about Oracle instance recovery? (Choose two.)

A.
Recovery begins from the beginning of the CURRENT redo log group.
B.
Recovery begins from the last checkpoint position that was calculated by the
Database Writer before instance failure.
C.
Recovery begins from the start of any ACTIVE redo log group or the start of
The CURRENT log group if no other group is ACTIVE.
D.
Recovery reads redo until the end of the redo thread. SMON rolls back any
Dead transactions, and then the database is opened.
E.
Recovery begins from the last checkpoint position that was recorded in the
Control file by the checkpoint process (CKPT).
F.
Recovery reads redo until the end of the redo thread, and then opens the
Database. SMON then rolls back any dead transactions.