题目

How often ______ he ______ in summer?     A does; swim   B is; swimming  C does; swims  D do; swims 答案：A 【解析】此题重点考查特殊疑问句的基本构成。特殊疑问词+助动词+主语+动词原形？我国地势西高东低，自西向东分成 级阶梯，我们所在的云贵高原属于第 级阶梯．