yo-yo

n.

溜溜球（一种线轴般的玩具）；优柔寡断的人；〈美俚〉蠢人，笨人；

adj.

上下起落的；摇摆不定的；

v.

玩约约；忽上忽下；

复数：yo-yos

1. The teacher threatened to confiscate their Yo Yos if they kept playing in class.
   老师威胁说，如果他们在上课时继续玩就没收他们的溜溜球。
2. Set knowledge, interest and entertainment with a convenience simple, but is free yo.
   设置一个方便简单的知识，兴趣和娱乐，但是是免费的溜溜球。

Yo-yo
Yo-yo
Yo-yo
The yo-yo intermittent recovery test: physiological response, reliability, and validity.
The Yo-Yo intermittent recovery test : a useful tool for evaluation of physical performance in intermittent sports
The Yo-Yo IR2 test: physiological response, reliability, and application to elite soccer
Aerobic fitness and yo-yo continuous and intermittent tests performances in soccer players: a correlation study.
The Yo-Yo Intermittent Recovery Test
Direct validity of the yo-yo intermittent recovery test in young team handball players.
Oscillatory neural networks for robotic yo-yo control
Toy yo-yo with selective enhanced rotation
Oscillatory neural networks for robotic yo-yo control
The SCAAR registry or the Swedish yo-yo