A. Only transactional and normal modes wait for all uncommitted transactions to commit or rollback and then close the database.
B. Immediate, transactional, and normal modes all result in a checkpoint.
C. Neither the immediate nor the abort mode rolls back uncommitted transactions.
D. Immediate, transactional, and normal modes wait for all uncommitted transactions either to commit or rollback and then close the database.
Correct Answer: AB
原文：http://blog.51cto.com/13854012/2153116