1 . In respect of satellite navigation (导航)，our country is firmly_____the lead now. (用适当的词填空)

2 . The programme showed those doctors and nurses _______special importance to any potential symptoms in the population.

A．attached	B．contributed
C．led	D．indicated

3 . It would be very safe if you_________ the door_________ to the garden.

A．fasten; led	B．will fasten; leads
C．fastened; leading	D．fastened; to lead