Which two statements are true？（）
- AIt is possible for more than two threads to deadlock at once.
- BThe JVM implementation guarantees that multiple threads cannot enter into a deadlocked state.
- CDeadlocked threads release once their sleep（） method’s sleep duration has expired.
- DDeadlocking can occur only when the wait（）， notify（）， and notifyAll（） methods are used incorrectly.
- EIt is possible for a single-threaded application to deadlock if synchronized blocks are used incorrectly.
- FIf a piece of code is capable of deadlocking， you cannot eliminate the possibility ofdeadlocking by insertinginvocations of Thread.yield（）.