第21题: [单项选择]Not until the bell had rung ______ the classroom in a hurry. A. he came into B. did he come into C. he has come into D. has he come into 参考答案:B 答案解析:[解析] 本题考查的是倒装句的用法。否定词或含有否定意义的词置于句首时,句子要部分倒装,故选项B为正确答案。
[避错指南] A项和C项中主语和谓语没有倒装,D项虽主谓倒装,但谓语时态没有与从句保持一