Please select the most similar patent number from A, B, C and D. Which number is?
A cascade pumped storage power station, comprising: a high-level water storage area, a middle-level water storage area (19), and a lower-level water storage area (20); water conveying channels (15) being in communication with the high-level water storage area and the middle-level water storage area (19) and in communication with the middle-level water storage area (19) and the lower-level water storage area (20); and two-way generator units provided between the high-level water storage area and the middle-level water storage area (19) and provided between the middle-level water storage area (19) and the lower-level water storage area (20), pumped storage or power generation being performed by utilizing the two-way generator units by means of the water conveying channels (15). According to a forming method of the cascade pumped storage power station, an underground water storage area is constructed by selecting an abandoned mine roadway, and at least the middle-level water storage area and the lower-level water storage area having a height difference are used as underground water storage areas.
A: A generator system for horizontal use and reutilization of hydroenergy comprises a reservoir disposed upstream of a river, a flow channel disposed on a riverbed in a flowing direction of the river, and multiple hydro turbine generator sets and a motor room (4) installed on the flow channel. The flow channel comprises a load bearing dike (1) and a sluice (2) disposed on the load bearing dike (1). The sluice (2) is provided with a water inlet (21) and a water outlet (22). The water inlet (21) is in communication with the reservoir and provided with a water inlet gate (23). The water outlet (22) is directed toward downstream of the river. The multiple hydro turbine generator sets are disposed at even intervals on the sluice. The generator system utilizes the variation of the height of natural water level and reutilizes the hydroenergy for power generation to obtain constant and stable electric energy.
B: A pedal-type mopping water bucket and a flat mop that matches same, comprising a bucket body (1) made of a plastic material. A water storage area (1b) and a washing and draining area (1c) that are independent of each other are disposed in the bucket body (1). A communication passage (A) is disposed between the water storage area (1b) and the washing and draining area (1c). A pedal (5) is disposed below the water storage area (1b) and the washing and draining area (1c), and the pedal (5) is connected to a lifting switch (4). When the pedal (5) is not depressed, the lifting switch (4) blocks the communication passage (A) between the water storage area (1b) and the washing and draining area (1c). When the pedal (5) is depressed, the lifting switch (4) leaves the communication passage (A) such that the water level is changed between the water storage area (1b) and the washing and draining area (1c) according to the principle of communicating vessels. A single bucket is internally and separately provided with a water storage area (1b) and a washing and draining area (1c), and when the water level flows therebetween, the cleaning and draining of a mop are integrally completed in a T-shaped port, and the foregoing bucket is convenient to use.
C: A water supplement device for a toilet bowl rim and toilet (20) having the same. Water draining of the water supplement device is independent of that of a toilet tank (30). The water supplement device comprises a water storage container (10), a water inlet (11) provided at the top of the water storage container (10), and a water draining opening provided on a bottom surface thereof, wherein the water draining opening is connected to a toilet bowl rim water passage. A flapper (40) for opening/closing the water draining opening is mounted in the water storage container (10). A water storage area (12) is provided in the water storage container (10) and comprises a flow guiding channel (13), wherein an end of the flow guiding channel (13) is connected to the water inlet (11), and the other end extends to the water storage area (12), and is located below a maximum water level of the water storage area (12) or level with the maximum water level of the water storage area (12).
D: A water dispensing device, a water dispensing system, a control method for a water dispensing device, and a storage medium. The water dispensing device comprises: a body (102), wherein a water receiving area (104) is provided on the body (102); a water storage apparatus, which is provided on the body (102); a detection apparatus (106) provided on the body (102), wherein the detection apparatus (106) can transmit and receive a frequency-modulated continuous wave; a storage apparatus, wherein the storage apparatus stores a computer program; and a control apparatus, wherein when executing the computer program, the control apparatus realizes: controlling the detection apparatus (106) to transmit a frequency-modulated continuous wave to the water receiving area (104) (step 202); controlling the detection apparatus (106) to receive a first reflected wave which is formed after the frequency-modulated continuous wave is reflected by a water receiving container (108) (step 204); and according to the frequency-modulated continuous wave and the first reflected wave, controlling the water storage apparatus to output water (step 206). By means of the water dispensing device, non-contact automatic water output control of the water dispensing device can be realized, the control accuracy is improved, and control is realized in a more reliable manner.
Answer: A