只有少数学生能够理解这个复杂的概念，其他学生都感到非常困惑，以至于有些不耐烦了。(handful)

Only a handful of students can understand this complex concept, while the rest of the students feel so extremely confused that they become a little impatient.

考查固定短语和时态。表示 “只有少数学生” 翻译为only a handful of students，作主语；表示 “理解” 用动词understand，can后跟动词原形；表示 “这个复杂的概念” 为this complex concept；while表示前后文的对比关系；表示 “其他学生” 用the rest of the students；此处为句型 “so ... that ...”；表示 “感到非常困惑” 可用feel so extremely confused；that从句主语为they；表示 “有些不耐烦” 可用become a little impatient，描述特定语境为一般现在时。故翻译为：“Only a handful of students can understand this complex concept, while the rest of the students feel so extremely confused that they become a little impatient.”。