Three-dimensional agriculture refers to the full use of the complex population of crops in space and time. According to the different characteristics of different crops, such as high stalks and short stalks, rich light and shade tolerance, early and late maturity, deep and shallow roots, leguminous and gramineous, use Their time and space differences in the growth process, and reasonable implementation of scientific intercropping, interplanting, mixed seeding, rotation and other supporting planting, forming a multi-crop, multi-level, multi-time-dimensional three-dimensional cross-planting structure. According to the above definitions, Which of the following are three-dimensional agriculture:. ['A grows soybeans in his own cornfield.', 'B not only raises fish in his contracted fish pond, but also planted many lotus roots.', 'C contracted ten acres of rice fields in a certain area in the south, and introduced new high-yielding rice varieties.', 'Ding Qian contracted a mountain. He planted a lot of apple trees on the mountain and raised a lot of bees on the mountain.']