The period of adolescence may be long or short, depending on social______and on society de

The history of English can be divided into three periods: Old English, Middle English

The period of adolescence, i.e. , the person between childhood and adulthood, may be long

Which of the following industries will probably be a good indicator of a period of expansi

The cooling water temperature should be gradually reduced over a period of （),and then sh

During the period of ______ from oil heat to gas heat the furnace will have to be shut off

The period of adolescence is much longer in industrial societies because ______.A．the defi