True for a 2yrs old boy is

At 2yrs weight becomes 4 times that of bih ( at bih 3kgs, at 2yrs 12kgs) A child is able to ride a bicycle by the age of 3yrs A child is able to climb up and down the stairs at 4yrs Ossification center for radius head appears at 3-4 yrs of age. Ref: Ghai ,9th edition, chapter 2 & 3.