中间等级

Scientists on Wednesday raised the alert level for Anak Krakatoa and Tangkuban Prahu -- which regularly spew gas and rumble -- from "normal" to "warning," the middle of three alert levels.

上周三，科学家们将喀拉喀托山和唐库班珀拉胡山度由“正常”提高到“告”，三中间等，因为这山近来定期喷出山灰，并发出隆隆声音。