Both strains quickly invaded local hospitals when needle sharing and other unhealthy practices ensured the rapid spreading of the infection by bringing people into contact with contaminated body fluids.
出自-2013年6月聽力原文
柯林斯高階英漢雙解學習詞典釋義
VERB
保證;確保;擔保
To ensure something, or to ensure that something happens, means to make certain that it happens.