【简答题】在等差数列 中, , ,则 ______;设 ,则数列 的前 项和 ______.
【简答题】设数列 的前 项和 ,则 = ____________.
【简答题】设a≡b(modm),若d|m和d|a,则d|b. 设a≡b(modm),若d|a和d|b,则d|m?
【单选题】Task 2 Directions: This task is the same as Task 1. The 5 questions or unfinished statements are numbered 41 through 45. Most nations of the world export goods to other countries. Likewise, many impor...
【简答题】()是政府采购中最常采用的采购方式之一。