You always spend only a little time on your study.You really _____ me down.— I’m sorry, Mum. I won’t do that again.

His film is sure to win the award because it ____ by most people

The guide said that much attention must ______ these details.

Last term our maths teacher set so difficult an examination problem _____ none of us worked out.

下列各句中，没有语病且句子表意明确的是 （ ）