The past perfect (had + VERBed) serves to express an action COMPLETED before another past event.In 1981 children in the United States spent an average of slightly less than two and a half hours a week doing household chores; by 1997 they had spent nearly six hours a week.
A. chores; by 1997 they had spent nearly six hours a week
B. chores; by 1997 that figure had grown to nearly six hours a week
C. chores, whereas nearly six hours a week were spent in 1997
D. chores, compared with a figure of nearly six hours a week in 1997
E. chores, that figure growing to nearly six hours a week in 1997
had + VERBed cannot serve to express an ONGOING action.
A: by 1997 they had spent nearly six hours a week
Here, had spent (past perfect) incorrectly serves to express an ONGOING action that is performed SIX HOURS A WEEK.
Eliminate A.
whereas must serve to contrast subjects that can logically be compared.
In C, it is illogical to compare children (the subject of the first clause) to six hours (the subject of the second clause).
Eliminate C.
A COMMA + VERBed modifier must serve to modify the nearest preceding noun.
In D, compared seems to refer to chores -- the nearest preceding noun -- implying that CHORES are compared with a figure.
This comparison is illogical.
Eliminate D.
A VERBing modifier must serve to express a CONTEMPORANEOUS action: an action happening at the SAME TIME as the main verb.
In E, the usage of growing implies that that figure was GROWING IN 1997 at the same time as children SPENT LESS THAN TWO AND A HALF HOURS IN 1981 -- an illogical sequence.
Eliminate E.
The correct answer is B.
