| Share | Phrase |
|---|
| 33.79% | spontaneously [manner] ignite |
| 11.54% | spontaneously [manner] tend |
| 10.82% | spontaneously combustible |
| 10.67% | spontaneously [manner] combust |
| 9.48% | spontaneously [manner] oil |
| 6.82% | spontaneously [manner] react |
| 6.41% | spontaneously [manner] release |
| 5.56% | spontaneously [manner] occur |
| 4.86% | spontaneously [manner] return |