No one drug will suit or work for everyone and sometimes several may have to be tried.
没有任何一种药会对每个人都适用或有效，有时得试好几种。
《柯林斯英汉双解大词典》
2
One of them is a word counter, which counts for certain word occurrence in several files.
其中之一是单词计数器，它统计某一单词在几个文件中出现的次数。
3
One longtime critic, Les Perelman, has drawn national attention several times for putting together nonsense essays that have fooled software grading programs into giving high marks.