请看这个题目，选哪个最佳？
_________ was very _________ that little Jim wrote the letter.
A. It, careful B. It, carefully C. He, careful D. He, carefully
【分析】此题正确答案为B，其余几项均有可能被误选。误选的原因主要是将第二空所填之词视为动词 was 的表语，从而误选了形容词 careful，并以此为依据在第一空误填了代词 He，误认为 He was very careful 是一个句子意群。其实，此题是一个强调句，其非强调形式为 Little Jim wrote the letter very carefully. 若用 it is … that… 的强调句式强调其中的状语 very carefully 即为上面一题的题干。请看下面几例，也属强调结构：
(1) It was when she was about to go to bed _________ the telephon
