How do I play the sweeping strings of the guzheng? Please describe in detail

Sweeping the strings is plucking the strings inward or outward with the left or right hand, depending on the overall feeling of the piece, it can be soft or thick. Generally speaking, the first few strings of an inward sweep are plucked with a tight focus, and the more you pluck, the lighter the force and the slower the speed is compared to the previous one. Sweeping the strings backward is generally sweeping the bass region, generally more thick

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