当老板要求他加班时，他突然拒绝了这个请求。

He suddenly ___balked when the boss asked him to work overtime.

马匹在悬崖边突然停下，不肯再往前走了。

The horse ___balked at the edge of the cliff and refused to move forward.

裁判判定投手犯规，因为他做了一个欺骗性动作。

The umpire called a ___balk because the pitcher made a deceptive move.