____new wave of Chinese migration is under way, fuelled by ever-younger students for whom

English is not a piece of knowledge but a living language to unlock ____ door of the wider world.

A．The; the

B．The; a

C．A; the

D．A; a

具体行政行为生效后，非因法定事由和依法定程序不得随意变更、撤销，体现的是行政行为的拘束力。( )