Please select the most similar patent number from A, B, C and D. Which number is?
A suction nozzle structure for a massage device. A suction nozzle (20) is made of a flexible material, and the suction nozzle (20) has a trumpet-shaped cavity (201) with an outward opening. The inner bottom face of the cavity (201) is integrally convexly provided with a toggle piece (21) facing the opening of the cavity (201), and a support part (22) is formed on a back face of the toggle piece (21). The toggle piece (21) sways left and right to squeeze the air in the cavity (201), thereby generating an air vortex. The surface of a human body is massaged by using a force generated by the air vortex, so that the traditional manner of using an object to directly act on the human body is replaced, and the user experience can be effectively improved.
A: Provided is a massager, comprising: a control mechanism (20) comprising a case, the case being a hard shell, and the case being provided with a wearing recess (201) adapted to the patella of a user, with an opening of the wearing recess (201) of the case abutting against the periphery of the patella; and a fixing mechanism (30), which is connected to the case and is wound around and fixed to the knee area of the user together with the case so as to hold the patella of the user in the wearing recess (201), wherein the fixing mechanism (30) is provided with a massage airbag at a position corresponding to the knee area. Since the opening of the wearing recess (201) of the case abuts against the periphery of the patella, and the case is a hard shell, after the massage airbag is inflated, the fixing mechanism (30) necessarily applies a pulling force to both ends of the case, and the pulling force is delivered to the peripheral area of the patella, such that the case does not directly squeeze the patella, nor affects the user&#39;s sitting or walking, thereby avoiding a poor massage effect caused by improper squeezing on the patella.
B: A humidifier and a heater. The humidifier comprises a housing assembly (2), a cover assembly (1), an oscillation plate assembly (5), and a fan (3). A water storage cavity (20), an accommodation cavity (21), and an isolation column (22) are formed in an inner portion of the housing assembly (2). The water storage cavity (20) and the accommodation cavity (21) are isolated from each other in a vertical direction. The isolation column (22) extends from the accommodation cavity (21) into the water storage cavity (20). The water storage cavity (20) is formed into an open structure having an upwards-facing opening. The fan (3) is located in the accommodation cavity (21). An airflow generated by the fan (3) is introduced via the isolation column (22) into air in the water storage cavity (20). The humidifier uses the airflow generated by the fan (3) to discharge, via a steam discharging port (100), steam in an upper hollow portion of the water storage cavity (20) without requiring the additional and specific provision of a steam discharging pipeline, such that the overall structure of the humidifier is compact, thereby reducing the design dimensions of a product, and reducing the footprint thereof.
C: A hockey stick having a shock-absorbing function comprises a striking part (10) and a holding part (20) that are sequentially connected. The striking part (10) and the holding part (20) are both made of composite carbon fiber. The holding part (20) is hollow with a cavity (201) formed therein. The holding part (20) comprises a front section (21) and a rear section (22). The front section (21) and the rear section (22) are fixedly connected by a shock absorber (30) therebetween. The outer wall of the shock absorber (30) is exposed at the outer wall of the holding part (20), and the inner wall of the shock absorber (30) is exposed at the inner wall of the cavity (201).
D: Disclosed is a surface cleaning device, comprising a suction nozzle (2) for sucking up liquid from an object surface and outside air when cleaning the object surface; a water tank (3) which is provided with a cavity and used for collecting the liquid sucked up; a suction unit (4) for generating a negative pressure and forming a suction force; a suction pipeline (5) which is connected between the suction nozzle (2) and the water tank (3) and used for transferring the sucked-up liquid and outside air into the water tank (3); and a negative pressure pipeline (6) which is connected between the suction unit (4) and the water tank (3) and is in communication with the suction pipeline (5) via the cavity inside the water tank (3). The suction nozzle (2), the suction pipeline (5), the water tank (3), the negative pressure pipeline (6) and the suction unit (4) are arranged in sequence from top to bottom, the liquid and the outside air sucked up by the suction nozzle (2) enter the water tank (3) through the suction pipeline (5) along the same path from top to bottom, and the liquid sucked up by the suction nozzle (2) is collected by the water tank (3) after entering the water tank (3), while the outside air sucked up by the suction nozzle (2) continues to pass through the negative pressure pipeline (6) after entering the water tank (3) along a path from top to bottom and is discharged out by the suction unit (4). The surface cleaning device has a simple structure, and can quickly suck up liquid from the object surface and collect same in the water tank (3).
Answer: A