SC prep2008 就一个动词单复数的问题 求教～～！

miaoyulin

The thirteenoriginal British colonies in North America, some formed as commercialventures, others as religious havens, each had a written charter that setforth its form of government and the rights of the colonists.

A.    some formed as commercial ventures, others asreligious havens, each had a written charter

B.     some being formed as a commercial venture, othersas religious havens, all of which had written charters

C.    some that formed as commercial ventures, others asreligious havens, all had written charters

D.     with some beingformed as a commercial venture, others as religious havens, all had a writtencharter      (A)

E.     with some formed as commercial ventures, whileothers as religious havens, each had a written charter

OA： A
之前查了这道题，但是都没有有关后面那个set forth 的单复数解释。既然没划线的set 没有加s 为啥that 之前的个charter 是单数？？
求NN赐教！！！！！

wyw1018

set过去时现在时同形。

miaoyulin

好心人帮帮忙～～～