补全法
与省略法相反的是，在一些单项填空题中，句子省略了某些成分的特殊结构较大地增加了试题的难度，我们可运用分析句子结构的方法，补全句子，破解难点，寻求正确答案。
19. Though ______ money his parents managed to send him to university.
A. lacked B. lacking of C. lacking D. lacked in
对于此题，我们可以采用补全句子的方法寻找正确答案。将句子补全为：Though they lacked money his parents managed to send him to university. 这样，题干中they被省略了，lack与they呈主动关系，所以用现在分词形式，故正确答案为C.
在某些复合句中，从属连词when if once though as soon as while等引导的从句，从句的主语与主句的主语相同，常将从句的主语和谓语be动词省略，或省略主语，谓语动词采用分词形式。
20. Boris has brains. In fact I doubt whether anyone in the class has ______ IQ.
A. a high B. a higher C. the higher D. the highest
通过分析句子结构，该题省略了than he does. 将其补全应为：Boris has brains. In fact I doubt whether anyone in the class has ______ IQ than he does. 所以应用比较级，并且此处的比较级表达最高级的含义，从而得出正确答案为B.
21. ----What made her mother so angry?
---- ______ the exam.
A. Because she didnt pass B. Her not passing
C. She didnt D. Because her not passing
通过分析句子结构，将答语部分补全为：_____ the exam made her mother so angry. 可以看出少了一个主语，而能用作主语的是答案B. 这个选项是一个动名词的复合结构。