题目

Luckily, we'd brought a mad map without _______ we would have lost our way. A. it                            B. that C. this                          D. which   答案：Dwhich指先行词a road map， 本题考查了介词without加关系代词which的用法。  已知{ a n }是公差不为0的等差数列，且a n ≥ 0；又定义b n =+ ( 1 ≤ n ≤ 2003 )，则{ b n }的最大项是（   ）（A）b 1001          （B）b 1002          （C）b 2003          （D）不能确定的