You are _________ careful than your brother. You two can't do the work that needs care and skill.
A. not more B. no more C. not less D. no less

选对此题，至少要弄清两点：一是下文的语境，二是 not more than, no more than等结构的含义。下文说You two can't do the work that needs care and skill（你们两个都不适合做这需要细心和技巧的工作），这就表明这两个人都不是很仔细的人。

再看选项中所涉及的几个结构的意思：

not more ... than = 不如

no more ... than = 和......一样不(否定两者)

not less ... than = 不如......不（即指不如 less 后形容词的反面）

no less ... than = 和......一样(肯定两者)

比较以下各句的意思：

You are more careful than he is. 你比他仔细。

You are not more careful than he is. 你不如他仔细。

You are no more careful than he is. 你和他一样不仔细。

You are less careful than he is. 你不如他仔细（你比他粗心）。

You are not less careful than he is. 你比他仔细（你不如他粗心）。

You are no less careful than he is. 你和他一样仔细。

综合以上分析，上面一题的最佳答案应是B。