单项选择题Four mutually exclusive projects have been appraised using NPV, IRR, ROCE, and PP. the company objective is to maximize shareholder wealth. Which should be chose? NPV IRR ROCE PP project A 1.1m 24% 35% 2.5 years project C 1.5m 12% 18% 7 years A、project A B、project B C、project C D、project D

单项选择题通过在过滤介质下方抽真空，增加过滤介质两侧压力差，达到加快过滤速度的过滤操作的是( ) A、薄膜过滤 B、超滤 C、减压过滤 D、常压过滤