题目

I’ll never forget the pleasant days ______ I spent with you.    A. /                 B. when                C. on which                 D. on that 答案：A 解析: 该句为定语从句，先行词作spent的宾语，作宾语的关系代词可以省略。5．$\frac{3}{4}$时=45分；        $\frac{2}{5}$吨=400千克．