Due to the destruction of human activities and the constraints of natural factors, it has not been replenished for many years, and soil erosion has become increasingly serious. At present, no suitable recycling method has been found, and the future of land is worthy of continuous attention. Change the long-established working habits in agriculture It doesn't happen in a day, and the main thing is to change the production mode of agriculture, which requires an increase in productivity, which obviously cannot be achieved overnight. What does "this" refer to? ["People's continued attention.", 'Changing the long-established working habits in agriculture.', 'Changing agricultural production models.', 'Finding the right loop.']