13 : : 3 5 2556 .................. 1 3 , , 3 1 2. 3 1 3 50-52 .

. 1 2555 20.2

20 20.45 , 18.25 20.40 1 WHO 10

13.55 3

. . 3

One Child OK :1 1 0-Net 1 2 35.87% .

. 1

1 1 one child OK (one knowlage)

big book 100 100

30 400

.

.. . . . 20-30 . . .

212

.

3 1. 2. 3.

.

.. .

.

56