1-Large deposits of platinum ...........in South America in the eighteenth century.
a)was discovered
b)discovered
c)have discovered
d)were discovered
2-Because it ............so many substances,alchol .............as a solvent in making varnishes for wood.
a)dissolves/is used
b)dissolved/used
c)is dissolved/using
d)dissolving/was used
3-As a rule,members of this tribe .............to marry with each other.
a)isn't allowed
b)don't allow
c)aren't allow
d)haven't allowed
4-While that great tower .............,many people .............there due to the accidents.
a)was built/were died
b)built/died
c)was being built/died
d)has been built/had died
5-In future,most probably,such creature in the forests,since most have begun to die one by one.
a)may not be seen
b)might have been seen
c)cannot see
)will be seen
6-The pain of a stomatch ulcer ..............by eating something.
a)can be relieved
b)may relieve
c)should have been relieved
d)had better relieve
7-A person who ..............by everybody .............more careful about his behaviors.
a)is known/should be
b)known/has to be
c)knowing/can be
d)has known/must have been
8-In the experiment,the cylinder .............by a layer of tin foll.
a)covers
b)covered
c)was covered
d)are covered
9-The illustration of books,which ............"illumination", ..............by the artists.
a)called/was practised
b)is called/is practised
c)was called/practised
d)called/was practising
10-Advertising ............with the invention of printing and ..........as an art now.
a)begins/considers
b)was begun/was considered
c)has been begun/considered
d)began/is considered