Abstract: A toilet tank structure is formed by a primary-secondary water tank set, a tap water inlet control valve, a secondary water tank inlet control valve and a flush control module, and the tap water inlet control valve, the secondary water tank inlet control valve and the flush control module are provided for controlling the flushing and water supply to minimize the waste of water resources effectively, so as to achieve the effects of saving water and improving functionality.

Abstract: A toilet tank structure is formed by a primary-secondary water tank set, a tap water inlet control valve, a secondary water tank inlet control valve and a flush control module, and the tap water inlet control valve, the secondary water tank inlet control valve and the flush control module are provided for controlling the flushing and water supply to minimize the waste of water resources effectively, so as to achieve the effects of saving water and improving functionality.

Abstract: A bike extendable crank includes an extendable crank unit. The extendable crank unit includes an immovable crank and a movable crank. The immovable crank has a slide trough therein, a limit groove at one side thereof and a main axle hole above the limit groove. One end of the movable crank has a first pivot hole for connection of a pedal and another end of the movable crank has a second pivot hole for connection a guide axle. The movable crank is slidably received in the slide trough of the immovable crank. The guide axle inserting through the second pivot hole of the movable crank slides in the limit groove of the immovable crank.