a bear contract的用法和样例：
- Her husband is such a bear that nobody likes him.
- The pendulum of the clock in my room is a bear.
- There is a bear in the inmost recesses of the cave.
- He must have iron nails that scratches a bear.
- When he's just woken up he's like a bear with a sore head.
- But the arrival of a bear market makes more bodies in considering how to adjust the operating strategy, so that investors Callable Bull / Bear Contracts are in the city to make money.