β-转角（β-turn）

turn over a new leaf

Theory is based on practice and( )turn serves practice.

A:in B:by C:at D:on

Theory is based on practice and（）turn serves practice.

A:in B:by C:at D:on

Theory is based on practice and( )turn serves practice.

A:in B:by C:at D:on

（）you turn on Home With Kids (家有儿女), you'll never be able to turn the TV off.

A:If B:Because C:Although D:As