Please let me know the correct answers to the below questions

611.Roy Wilkins was among the last of a generation of civil rights activists who led the nation through decades of change so profound many young Americans are not able to imagine, even less to remember, what segregation was like.
(A) so profound many young Americans are not able to imagine, even less to remember
(B) so profound that many young Americans cannot imagine, much less remember
(C) so profound many young Americans cannot imagine nor even less remember
(D) of such profundity many young Americans cannot imagine, even less can they remember
(E) of such profundity that many young Americans are not able to imagine, much less to remember

I chose answer : B

618. School integration plans that involve busing between suburban and central-city areas have contributed, according to a recent study, to significant increases in housing integration, which, in turn, reduces any future need for busing.
(A) significant increases in housing integration, which, in turn, reduces
(B) significant integration increases in housing, which, in turn, reduces
(C) increase housing integration significantly, which, in turn, reduces
(D) increase housing integration significantly, in turn reducing
(E) significantly increase housing integration, which, in turn, reduce

IMO E

629.Seeming to be one of the few corporations diversified enough to survive the recession, many shareholders ignored the drop in third-quarter profits and invested even more heavily in Emco.
(A) Seeming to be
(B) As if
(C) In that they seemed
(D) Although it seemed
(E) Because it seemed to be

IMO : E

630. Seeming to be the only organization fighting for the rights of poor people in the South, Hosea Hudson, a laborer in Alabama, joined the Communist party in 1931.
(A) Seeming to be
(B) As
(C) In that they seemed
(D) Since it seemed
(E) Because it seemed to be

IMO : B

638. Several years ago the diet industry introduced a variety of appetite suppressants, but some of these drugs caused stomach disorders severe enough to have them banned by the Food and Drug Administration.
(A) stomach disorders severe enough to have them
(B) stomach disorders that were severe enough so they were
(C) stomach disorders of such severity so as to be
(D) such severe stomach disorders that they were
(E) such severe stomach disorders as to be

IMO D

639. Severe and increasing numerous critics are pointing to deficiencies in the British legal system, deficiencies that seem to deny a proper defense to many clients who are charged with crimes.
(A) Severe and increasing numerous critics are pointing to deficiencies in the British legal system, deficiencies that seem
(B) Severe and increasing numerous critics point to deficiencies in the British legal system, deficiencies seeming
(C) Severe and increasingly numerous critics are pointing to deficiencies in the British legal system that seem
(D) Severely and increasingly numerous critics point to deficiencies in the British legal system seeming
(E) Severely and increasingly numerous critics are pointing to deficiencies in the British legal system that seem

IMO C

641. Similar to rising interest rates, consumer and producer prices have been rising.
(A) Similar to rising interest rates, consumer and producer prices have been rising.
(B) Consumer and producer prices have been rising, as have interest rates.
(C) As interest rates are rising, so have consumer and producer prices.
(D) Consumer and producer prices have been rising, like interest rates do.
(E) Consumer and producer prices, as interest rates, have been rising.

IMO B

Any help,much appreciated.
Thanks!