The two-month development indicators for infants are: height, 55.5-60.7cm for boys and 54.4-59.2cm for girls; weight, 4.3-6.0kg for boys and 4.0-5.4kg for girls; head circumference, about 39.84cm for boys and 38.67cm for girls; chest circumference, about 40.10cm for boys and 39.05cm for daughters; holding a 2-month-old baby upright, the head can stand up straight, almost without support. 2-month-old babies start to be interested in their own hands, usually look at their own little hands, and will put the whole hand into their mouths to eat, and they have a sensitive sense of hearing, their heads will turn in the direction of sound, and their eyes will stare at bright colors, such as red or orange. 2-month-old babies laugh easily, can make simple ah, ee, ah vowels, and are affectionate to those who have taken care of them for long periods of time. They are very affectionate to those who have been caring for them for a long time.