—What's the matter with Tim
—Oh, Tim's cellphone was left in a taxi accidentally, never（）again.

A:to find B:to be found C:finding D:being found

Files can be lost or destroyed accidentally. Keep (72) copies of all data on removable storage media。

A:back B:black C:backdown D:backup

Files can be lost or destroyed accidentally．Keep (74) copies of all data on removable storage medi

A:backup B:back C:black D:backdo

Files can be lost or destroyed accidentally．Keep ______ copies of all data on removable storage media.

A:backup B:back C:black D:backdown

Files can be lost or destroyed accidentally. Keep（）copies of all data on removable storage media.

A:backup B:back C:black D:backdown

—What's the matter with Tim
—Oh, Tim's cellphone was left in a taxi accidentally, never（）again.

A:to find B:to be found C:finding D:being found

—What's the matter with Tim
—Oh, Tim's cellphone was left in a taxi accidentally, never（）again.

A:to find B:to be found C:finding D:being found