Four-month-old Timothy takes his mother’s keys and begins to put them into his mouth but then discovers that when he shakes them, they make a pleasant sound. Timothy’s treatment of the keys demonstrates which concept of Piaget’s theory?

Compared with newborns who were conceived at the same time but born later, very low-birthweight infants begin to ______ later in life

eat sleep cry communicate

In 1970, about ______ percent of newborns in China were low birthweight; now it is estimated that ______ percent are born low birthweight

15; 50 50; 50 15; 55 50; 15