11: Cash flows to stock and bond mutual funds have gained strength in the last two months, but fund managers have not been eager to invest the new money, instead of preferring to raise the cash levels in their portfolios at the highest level in six months (?). a b
A: have not been eager to invest the new money, instead of preferring to raise the cash levels in their portfolios at
B: have not been eager to invest the new money, instead preferring to raise the cash levels in their portfolios to
C: have not been eager at investing the new money, instead of preferring to raise the cash levels in thief portfolios to
D: were not eager to invest the new money, instead of preferring to raise the cash levels the cash levels in their portfolios at
E: were not eager at investing the new money, instead preferring to raise the cash levels in their portfolios to我的问题是A为什么不对呀？为什么前面是have not been 而后面用preferring，是不是为了表示ongoing的状态？谢谢了