单选题 Not until recent years ______ a popular means of communication.
A. e-mail became B. e-mail has become
C. did e-mail become D. will e-mail become

【正确答案】 C

【答案解析】本题测试倒装句的用法。句首为否定词或否定意义的词语时，常用部分倒装(有时要借助助动词do等)。本句句首为not until，所以要使用部分倒装。这样表示否定的词或词组主要有：hardly，little，never，by no means，no sooner等。所以首先要排除A和B；其次根据信息词recent years判断句子不能用将来时，故答案为C