六级Ogbeh says experts are investigating how to control the pests damage and prevent its spread, which has gone largely unchecked until now.
奥格贝说,专家们正在研究如何控制害虫的危害并防止其传播,到目前为止,害虫的传播基本上没有受到控制。
2017年12月六级真题(第一套)阅读 Section A