1.Portland，Maine，is _____ the poet Henry Wadsworth Longfellow spent his early years.
where
it where
where is
which is where
2.As consumersresponse to traditional advertising techniques declines，businesses are beginning _____ new methods of reaching customers.
the development that
it developing
develop
to develop
3.The knee is _____ most other joints in the body because it cannot twist without injury.
more likely to be damaged than
likely to be more than damaged
more than likely to be damaged
to be damaged more than likely
4.The quince is an attractive shruborsmall tree _____ closely related to the apple and pear trees.
is
that is
that it is
is that which
5.Many gases，including the nitrogen and oxygen in air，_____ colororodor.
have no
which have no
not having
they do not have
6.The American Academy of Poets，_____ the 1930s，provides financial assistance to support working poets.
when it was founded
was founded
which was founded in
was founded in