A man escaped from the prison last night. It was a long time ________ the guards discovered what had happened.

1. A.
   before
2. B.
   until
3. C.
   since
4. D.
   when

A man escaped from the prison last night. It was a long time ________ the guards discovered what had happened.

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A man escaped from the prison last night. It was a long time ________ the guards discovered what had happened.

A. before　　　　　　   B. until　　　　　　　　  C. since　　　　　　　　 D. when

A. before　　　　　　   B. until　　　　　　　　  C. since　　　　　　　　 D. when

A man escaped from the prison last night. It was a long time ________ the guards discovered what had happened.

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