Remove the tank cover and check the water level after the fill valve has shut off. It should be about one inch below the opening of the overflow tube. If it is significantly lower than that, there may not be enough water in the tank to fill the bowl after a flush. Correct this by adjusting the float.
The average child can do this during the second half of this year. Between 24-36 months, children are typically able to work simple insert puzzles (e.g., completes a three-piece simple puzzle where pieces are whole objects). Also, children can remove a part from a toy (e.g., a wheel) and replace it.
By the end of 24 months, your child will say new words on a regular basis and use simple two-to three-word sentences and questions as well as start using pronouns. He or she will also understand simple instructions without gestures.