原级：reversal
1. Unforeseen economic reversals and the need to win the approval of skeptical regulators raise further challenges.
2. But some places had notable reversals in rank, including the former Soviet Union.
3. The lives of the ordinary people in her stories are put through intense and tumultuous reversals - not unlike the heroes in a Greek tragedy.
4. With such reversals and inconsistency, how can he expect to win public trust?
5. Podesta said Obama's aides were poring over all of them and will make such reversals among the new president's first acts.