After studying various reasons for the fouls occurred at the take-off in long jump, the author believes that a good consciousness control ability plays a key role in the accuracy of board take-off, which will be a certain theoretical basis for the improvement of the take-off success rate.

Because some learner drivers are inclined to press the accelerator pedal as the braking pedal mistakenly in an emergency,the concept design to install a device for preventing this behavior is advanced here.

Introduces the construction and principle of the instrument for testing the force and range of the automobile brake pedal and its calibrater as well as the methods of calibrating and testing the brake pedal range.