Three hundred firemen raced to the hotel after a smoke detector(检测器)_____ the alarm soon after midnight.
The police have ____ power to deal with such matters by ____ law.
That she hadn’t kept her ____ on her work resulted in the failure.
The little girl couldn’t work the problem out. She wasn’t ____ clever.
Listen! His family must be quarrelling, ____?
The engineers made two big plans for the dam, ____ was never put in force.