21.   These vital machines are used at coal faces and driveways.

22.   At school I used to read, mostly,

23.   This is the form which police officers use at the scene of an accident to describe the location and manoeuvres of vehicles.

24.   All were used at the time of the Edgar Ordo.

25.   It can penetrate fog and cloud, and can also be used at night.

26.   It was the kind of notepaper being used at the Zoological Society at the time, and completely unlike anything ever used by Darwin.

27.   Most of the CD-ROM databases being used at present are, not surprisingly, strongly bibliographic in character.

28.   Information about modules might be used at another time when designing another course.

29.   However, assembly is not widely used at present and as more companies develop RISCs it is likely that this architecture will dominate the CISC design in the future.

30.   The masses of materials used at each stage must equal the masses of material produced.