`1.` Computers are used for different purposes.

`2.` A very good program for the company  was written.

`3.` Information  in optical disks is held in some modern systems.

`4.` The first analogue computer was built  by an American named Van Var Bush.

`5.` Computers were designed to process information called data.

`6.` The  drug-detecting in the Tour de France is supported.

`7.` These CD ROMs are sent  to us.

`8.` The  barcode  was told to be read.

`9.` This train ticket was ordered for his mother by Tim using this  website.

`10.` She was shown how to use the  printer.

`11.` The pulses are sent to the branch computer.

`12.` The barcode is converted into electrical pulses.

`13.` The item is scanned by the checkout  operator.

`14.` The sale of the product is recorded.

`15.` The time each vehicle passes  is recorded.

`16.` Each vehicle is matched with the DVLC database.

`-` `-` `-` `-` `-` `-` `-` `-` 

${\text{Giải thích: }}$

`-` Cấu trúc bị động HTĐ: S `+` am/is/are `+` V3/V-ed... (by + O)

`-` Cấu trúc bị động qkđ: S `+` was/were `+` V-ed/V3… (by + O)

`+` Các đại từ bất định như somebody, nobody, people,..  không dùng by + O.