Look at the sentences, and decide which are the historical factors influencing childhood they refer to.（)

A.Today, children have few responsibilities, their lives are characterized by play not work, school not paid labor, family rather than public life and consumption instead of production.

B.In contrast, children on the Pacific island of Tonga, studied by Helen Morton, are regularly beaten by their parents and older siblings.They are seen as being closer to mad people than adults because they lack the highly prized quality of social competence (or poto as the Tongans call it).

C.Today, a four year old who can tie his or her shoes is impressive.In colonial times, four-year-old girls knitted stockings and mittens and could produce intricate embroidery: At age six they spun wool.

D.While Westerners might take exception to eight-year-old girls working or to 12-year-old girls marrying, within their own communities such activities are seen as a normal and positive part of childhood.