1.   An investigation has failed to discover the cause of the epidemic.

2.   Fire officers are still trying to discover the cause of the fire.

3.   His glee made Bowring nervous about discovering its cause.

4.   Once these causes are discovered we no longer have a miracle, but natural law...

5.   Relying on tablets for the relief of pain without trying to discover its cause can be positively dangerous.

6.   The police are making inquiries to discover the cause of the accident.

7.   We too had a humming in the dead of night for about two years until we discovered the cause.

8.   What is more important is to discover the causes of delay, without which general conclusions are likely to be unhelpful.

9.   This morning, however, a firemen accidentally discovered the cause.

10.   Scientists in both continents are now working discover the cause of the plague, and how it could have spread to Europe.