单项选择题
A．the training that parents received B．the age of the children C．the books that were read D．the number of the children
A．parents should be trained to read to their children B．the more children read, the more intelligent they will become C．children's language skills increase when they are required to respond actively D．children who read actively seem six months older
A．ate more food and had more physical activities B．ate less food but had more activities C．ate less food and had less physical exercise D．had more weight problems