人们跑来跑去,显然发生了不寻常的事情。 A: Peopleranbackandforth,obviously,somethingunusualhadhappened. B: Peoplewererunningbackandforth.Obviously,somethingunusualhadhappened. C: Peoplewererunningbackandforth.Obviously,somethingunusualhadbeenhappened. D: Peopleranbackandforth,obviously,somethingunusualhadbeenhappened.