问题
选择题
| _ of the mountains in that area covered with trees and grass. |
A. Two fifth; is B. Two fifth; are C. Two fifths; are D. Two fifths; is |
答案
答案：C
搜题请搜索小程序“爱下问搜题”
| _ of the mountains in that area covered with trees and grass. |
A. Two fifth; is B. Two fifth; are C. Two fifths; are D. Two fifths; is |
答案：C
某工程计划如图所示，由于任务A延迟了一天，为保证该工程按时完成，应将任务一缩短一天，使成本增加最少。下表列出了各任务每缩短一天所需增加的成本。
任务 | 每缩短一天需要增加的成本 |
| A | 4 |
| B | 6 |
| C | 3 |
| D | 2 |
| E | 2.5 |
| F | 2.5 |
| G | 5 |
A．B
B．C
C．D
D．E