1.Hundreds of huge wildfires have broken out all across the Arctic Circle.
break out 爆发
He was 29 when war broke out.
战争爆发时他才29岁 。
2.and warmer conditions encourage fires to grow and persist once they have been ignited.
persist 持续
If the symptoms persist, consult your doctor.
如果症状持续不消除,就得去看医生 。