OG13 16的C选项却have been thought的主语的问题

Leo冥

16. A surge in new home sales and a drop in weekly unemployment claims suggest that the economy might not be as weak as some analysts previously thought.
(A) claims suggest that the economy might not be as weak as some analysts previously thought
(B) claims suggests that the economy might not be so weak as some analysts have previously thought
(C) claims suggest that the economy might not be as weak as have been previously thought by some analysts
(D) claims, suggesting about the economy that it might not be so weak as previously thought by some analysts
(E) claims, suggesting the economy might not be as weak as previously thought to be by some analysts 17.

OG上C的解释说The sentence offers no plural subject to fit the passive verb have been thought，不太明白为什么这么解释

bejamin1111

the economy might not be as weak as 【the econemy】have been previously thought by some analysts

Leo冥

bejamin1111 发表于 2013-7-20 15:01
the economy might not be as weak as 【the econemy】have been previously thought by some analysts
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谢谢解答~