This bird is really lovely， and I’ve never seen ______ one.

Although he is old, he’s very          . However, when he was young, he was very lazy.

 With the help of the firefighters ,the workers managed to escape from burning mine , ___________.

If we are not _______ the progress we have made, we will have greater success. 

Lack food supplies and wanted by the police, the terrorists made a ______ attempt to hijack(劫持) a plane to Iran.