they searched for hours, but ____be found.
举一反三
- As they searched, they ________ in a notebook details of all the things they found.
- Having searched online for hours, the team finally ____________ about the causes of the problem.
- The police searched everywhere in the town ______ the three criminals, but they found none.
- 中国大学MOOC: The police searched the house but found no signs of a break-in.
- 18. _________ the library for hours without finding anything useful, I turned to my professor for help. A: To search B: Having searched C: Have searched D: Searching