山西焦煤《“三项建设”实施办法》中规定运输斜坡及车场经常保持清洁，做到（）。
A、无杂物
B、无碎石
C、无淤泥
D、无积水
参考答案：A, C, D
For an activity, the optimistic, most likely and pessimistic estimates are 12, 16 and 18 respectively. Which of the following statement is correct
A) There is 68.26% chance that the activity will be completed in 15 to 17 days. B) There is 95.44% chance that the activity will be completed in 15 to 17 days. C) There is 68.26% chance that the activity will be completed in 14.67 to 16.67 days. D) There is 93.73% chance that the activity will be completed in 15 to 17 days.
在强大竞争者的压力之下，企业的市场占有率（），在这种情况下，企业就需考虑降价。
A.下降
B.上升
C.波动
D.不变
