Due to repeated outbreak and protractedcourse of disease, the risk of cancerization of colitis is increasing and 40% colitis cases with more than 25 years disease course produce cancerization.
由于结肠炎症反复发作，迁延不愈，癌变风险不断升高，25年以上病程癌变率高达40%。
2
The paper discusses the pollution vanishing course under the natural condition and shows a protracted nature of the water pollution harm.
本文通过对自然条件下污染消退过程的探讨，揭示了水污染事件危害的长期性。
3
It's possible, of course, that the U. S. economy will relapse into a protracted recession and that interest rates will remain at rock bottom.