"In areas where the sleeping sickness is still very prevalent, such as remote areas of some central African countries -- which are by the way very unstable areas -- it will be also crucial to have simpler treatment and obviously oral treatment would be the best."

VOA: special.2010.04.07

These are elements that have yet to be isolated These are elements that are unstable.

这些元素还没有被提取出来,这些元素很不稳定。

麻省理工公开课 - 固态化学导论课程节选

Curtis says the surge will also reassure India that the Americans are there to stay and do not intend to cut and run, leaving behind an unstable Afghanistan and Pakistan, which would be a definite problem for India.

VOA: standard.2009.12.06

"In areas where the sleeping sickness is still very prevalent such as remote areas of some central African countries, which are by the way very unstable areas, it will be also crucial to have simpler treatment and obviously oral treatment would be the best."

VOA: standard.2010.04.05