求教GWD 20-32

Q32:  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.

1. claims suggest that the economy might not be as weak as some analysts previously thought

2. claims suggests that the economy might not be so weak as some analysts have previously thought
3. claims suggest that the economy might not be as weak as have been previously thought by some analysts

4. claims, suggesting about the economy that it might not be so weak as previously thought by some analysts
5. claims, suggesting the economy might not be as weak as previously thought to be by some analysts

作为答案的A项后面的previously thought为何说的通？用had previously thought是否更合适？

Past perfect tense can only be used if the sentence explicitly mentions a time in the past, and the action in question happened before that time. In this sentence, no such time is mentioned. Therefore, "had previously thought" is incorrect.