42. What do we know about Walter? (A) He is good at cooking. (B) He is the only child in the family. (C) He has lost his eraser several times. (D) He went shopping for food with his mom.

3. 設多項式函數 f (x) 的定義域包含區間[ a ，b] ，且在[ a ，b] 內 f (x)≥ 0 恆成立，n 為任意自然數，將區間[ a ，b] 平分成 n 等分，則 f (x) 在區間[ a ，b] 上的黎曼和。設 y= f(x) 、x 軸、直線 x = a 與 x = b 所圍成區域的面積為 A，則下列敘述何者錯誤？ (A) Rn 是 n 個矩形面積的和 (B)(C)對任意正整數 n 而言， A > Rn (D)若 f ( x) 在區間[ a ，b] 上為遞增，則 R 2<R4 。