Please select the most similar patent number from A, B, C and D. Which number is?
Disclosed is a roof greening and environmental protection self-watering system based on rainwater recycling technology. The system comprises a transverse rod (1), vertical columns (2), flowerpots (4), a watering pipe (6) and a water storage tank (8), wherein the several vertical columns (2) are uniformly arranged at a bottom end of the transverse rod (1), the water storage tank (8) is arranged below the transverse rod (1), and the several flowerpots (4) are uniformly arranged above the transverse rod (1). Several first support rods (3) are uniformly arranged at a bottom end of each flowerpot (4), a separation net (43) is arranged on the bottom of an inner cavity of each flowerpot (4), and the separation net (43) separates the inner cavity of the flowerpot (4) into an upper cavity and a lower cavity. A sand-gravel layer (41) and a soil layer (42) are provided in the upper cavity, and the soil layer (42) is provided in an inner hole of the sand-gravel layer (41). The watering pipe (6) is arranged above the flowerpots (4), several second support rods (5) are uniformly arranged at a bottom end of the watering pipe (6), and several drip nozzles (7) cooperating with the flowerpots are uniformly arranged on the watering pipe (6).
A: A flower pot, comprising a planting box (1), a water accumulation groove (2) and a water absorbent material (3); the planting box (1) and the water accumulation groove (2) are respectively provided with a convex guide strip (16, 16&#39;) inside the left and right sides at the junction therebetween; a plurality of convex strips (17) extend from the front face of the water accumulation groove (2) to the bottom face of the planting box (1); the convex strips (170, 170&#39;) on the left and right sides of the bottom face of the planting box play guiding and positioning roles when an upper and a lower flower pots are nested. The planting box (1) is provided with an inverted T-shaped hole (18) on the central end edge of the front face, and a drainage hole (12) between two adjacent convex ribs (13) on the bottom face; the long, flat water accumulation groove (2) is provided with a long groove (20&#39;) on the back face acting as a drainage channel thereof; the long groove (20&#39;) is internally provided with a hole (200&#39;) near the upper end edge acting as the spillway of the water accumulation groove, and a flanged strip (202) on the bottom face extending downward so that the drained water can smoothly flow into the flower pot below; the water absorbent material (3) is disposed between the planting box (1) and the water accumulation groove (2). In this way, the upper and lower flower pots can be simply and quickly nested. Furthermore, a plurality of gaps (4) are formed between the planting box and the water accumulation groove of the flower pot below, thus balancing the pressure and oxygen between the planting box and the water accumulation groove.
B: A self-cleaning environmentally friendly air purification and dust-removal device, comprising a wall (1), a purifier pipe (2), and a dust exhaust pipe (14); the purifier pipe (2) is embedded in the wall (1); a first protective mesh (3), a dust filter mesh (4), a motor (5), a gas distribution plate (7), a first filter layer (8), a second filter layer (9), an air suction fan (10), and a second protective mesh (12) are sequentially provided from left to right in an inner cavity of the purifier pipe (2); a cleaning brush (13), which cooperates with the dust filter mesh (4), is fixedly connected to a motor shaft of the motor (5); several ventilation holes (71) are uniformly provided on the gas distribution plate (7); an opening at the top of the dust exhaust pipe (14) is provided with a third protective mesh (17); a dust exhaust fan (15) is provided inside the dust exhaust pipe (14). By providing the dust filter mesh (4), the first filter layer (8), and the second filter layer (9), air is filtered and purified in many stages, removing impurities such as dust from air, purifying air, and improving indoor air quality. Dust accumulated on the dust filter mesh is removed when the motor (5) drives the cleaning brush (13) to rotate; moreover, the dust exhaust fan (15) discharges air and discharges dust to outdoor air, preventing dust accumulation from affecting the filter effect of the dust filter mesh (4).
C: A dust removal device for industrial fumes. The dust removal device comprises a dust removal housing (1), wherein a first filter screen (3) is arranged on the side of the inside of the dust removal housing (1) that is close to an air inlet (2); a support frame (4) is arranged on an outer side of the first filter screen (3); sliding grooves (5) are respectively provided on two sides of the support frame (4), and sliding blocks (6) are arranged inside the sliding grooves (5) in a sliding mode; a cleaning brush (7) is fixedly arranged between outer sides of the two sliding blocks (6), and a pull string (8) is fixedly arranged in the middle of the upper end of the cleaning brush (7); a water output pipe (9) is fixedly arranged at the top end of the interior of the dust removal housing (1), and several spray nozzles (10) are evenly arranged at the bottom end of the water output pipe (9) at intervals; a tapered shield (11) is arranged at the bottom end of the dust removal housing (1) and is located directly below the water output pipe (9); the bottom end of the tapered shield (11) is connected to a liquid discharging pipeline (12); a sealing piston (13) is arranged inside the liquid discharging pipeline (12); and a reset spring (14) is fixedly arranged at the bottom end of the sealing piston (13).
D: An environment-friendly air purifier for a public place, comprising a body (1). An air exhaust chamber (2), a disinfection chamber (3), an air entrainment chamber (4), and a filter chamber (5) are sequentially provided inside the body (1) from top to bottom. The bottom wall of the filter chamber (5) is connected to an air inlet (6) in a communicating manner. A protective mesh (22) is provided in the air inlet (6). A third filter layer (9), a second filter layer (8), and a first filter layer (7) are sequentially provided in the filter chamber (5) from top to bottom. A fan (11) is provided in the air entrainment chamber (4). Disinfection tubes (14) are provided in the middle of the disinfection chamber (3). Several lamp bases (16) are uniformly provided in the peripheral direction of the inner wall of the disinfection chamber (3), and ultraviolet radiators (17) are provided on the lamp bases (16). Plant filter cartridges (19) are provided in the air exhaust chamber (2), the side wall of the air exhaust chamber (2) is uniformly provided with several air exhaust holes (20), and the protective mesh (22) is provided in the air exhaust holes (20). The bottom end of the body (1) is uniformly provided with several supporting legs (21). Air is filtered layer by layer to ensure the exhausted air clean and environment-friendly.
Answer: A