11. 求 ∫_0^2 10^x dx ==？ (A) 99/( 10) (B)101/( 10) (C) 33 (D) 99

21. 下列各級數，何者一定不是交錯級數 ( alternating series )？ (A) \(1 - 2 + 3 - 4 + 5 - 6 + \cdots\) (B) \(1+2-3-4+5+6+7-8+\cdots\) (C) \( \frac{1}{1} - \frac{1}{3} + \frac{1}{5} - \frac{1}{7} + \frac{1}{9} - \frac{1}{11} + \cdots \) (D)\( \frac{1}{1} - \frac{1}{1} + \frac{1}{2} - \frac{1}{3} + \frac{1}{5} - \frac{1}{8} + \dots \)