a losing streak的用法和样例：
- Then there are those times when your bankroll can handle a losing streak but you can't.
- Cut your bets when in a losing streak and increase them when running in a spasm of good luck.
- All gamblers on a losing streak want to get their money back by continuing to gamble.
- But I know I'm on a losing streak
- I am sick and tried of fighting a losing battle.