题目

The number of traffic accidents caused by drinking is _____ as the number of those caused by non-drinking driving.     A. twice as many    B. many as twice   C. as twice large  D. twice as large 答案：D设f（x）是周期为2的奇函数，当x≥0时，f（x）=2x+2x+b（b为常数），则f（-52）= ．