1.___ has been known for about a hundred years, its commercial development has taken place since the beginning of the century.
A.WhichB.While
C.That
D.As
2.The elderly man who is moving the lawn is ___ the ,mayor himself.
A.no other butB.no other than
C.no one than
D.none other than
3.To succeed on a scientific research project, ___.
A.one needs to be persistentB.persistence is needed
C.one needs be a persistent person
D.persistence is one needs
4.Man has used metals for centuries in gradually increasing quantities but it was ___ the Industrial Revolution that they came to be employed in really vast quantities.
A.tillB.until
C.not until
D.not till
5.Peter has just arrived, but he talks as if he ___ everything here.
A.will knowB.has know
C.knew
D.know