Experts say children before the age of three with life in the most amazing ability to learn. This stage also lay their cognition of the world, and the future mode of learning.

专家说，三岁前的孩子拥有人生中最惊人的学习能力，此阶段亦奠定他们对这个世界的认知，以及未来的学习模式。

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The front stage uses the single-voltage-mode control strategy and the back stage uses the three states discrete pulse modulation hysteresis current control strategy.

前级采用电压单环调制方式，后级采用三态滞环离散脉冲调制电流滞环跟踪控制技术。

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