The little boy was so careless with his spelling that he often letters from words.A. left

问题补充：

The little boy was so careless with his spelling that he often letters from words.

A. left out

B. left behind

C. left off

D. let alone

答案：

A. left out

B. left behind

C. left off

D. let alone

解析：A

解析考查动词短语辨析。leave out遗漏；leave behind留下，遗留；leave off停止，中断；let alone更不用说。依据前面提及的careless可知，这里应该是将单词的字母遗漏了。故选A项。