Much research has been done on interviews in general ______.

A:but journalistic interviewing as a specific field has unfortunately been neglected B:though the study of the interviewing techniques hasn" t received much attention C:so the training of journalistic interviewers has likewise been strengthened D:and there has also been a dramatic growth in the study of journalistic interviewing

Joseph, the politician who（　）last week, has been released unharmed.

A:is kidnapped B:was kidnapped C:has been kidnapped D:had been kidnapped

Joseph, the politician who ______ last week, has been released unharmed.

A:is kidnapped B:was kidnapped C:has been kidnapped D:had been kidnapped

______ during the war, the airport has never been used again.

A:Has damaged B:Having damaged C:Has been damaged D:Having been damaged

(The metal) aluminum (has been) (first) isolated (early) in the nineteenth century.

A:The metal B:has been C:first D:early

Joseph, the politician who ______ last week, has been released unharmed.

A:is kidnapped B:was kidnapped C:has been kidnapped D:had been kidnapped

(The metal) aluminum (has been) (first) isolated (early) in the nineteenth century.

A:The metal B:has been C:first D:early