某工程由三个施工过程组成，它们分别由甲、乙、丙三个专业施工队完成。该工程在平面上划分A、B、C三个施工段，每个专业队伍在各施工段上的流水节拍如表13-5-1所示。则甲、乙和乙、丙两相邻主要施工队之间的流水步距分别为（）。
A．3d；4d
B．3d；5d
C．4d；2d
D．4d；5d
参考答案：D
解析：
该工程组织为非节奏流水施工，相应流水步距B甲-乙及B乙-丙应按“累加错位相减取大值”的方法计算，甲、乙、丙各专业队的累加数列分别为：
甲：4，6，11；乙：5，8，12；丙：4，8，11。
错位相减得：
甲与乙：
乙与丙：
取大值后得：B甲-乙=max(4，1，3，-12)=4，B乙-丙=max(5，4，4，-11)=5。
| When you first drift off into slumber, your eyes will roll about a bit, your temperature will drop slightly, your muscles will relax, and your breathing will become quite regular. Your brain waves slow down a bit, with the alpha rhythm predominating for the first few minutes. This is the first stage of sleep. For the next 30 minutes or so, you will drift down through Stage 2 and Stage 3. The lower your stage of sleep, the slower your brain waves will be. About 40-60 minutes after you lose consciousness, you will reach the last stage. Your brain waves will show the delta rhythm. You may think that you stay at this deep stage all the rest of the night, but that turns out not to be the case. About 80 minutes after you fall into slumber, your activity cycle will increase slightly. The delta rhythm will disappear, to be replaced by the activity pattern of brain waves. Your eyes will begin to dart around under your closed eyelids. This period of Rapid Eye Movements lasts for 8-15 minutes and is called REM sleep. During both light and deep sleep, the muscles in your body are relaxed but capable of movement. As you slip into REM sleep, a very odd thing occurs -- most of the voluntary muscles in your body become paralyzed. Although your brain shows very rapid bursts of neural activity during REM sleep, your body is incapable of moving. REM sleep is accompanied by extensive muscular inhibition. |
After you have reached the deepest sleep,______.
A．you will stay at the fourih stage the rest of the night
B．you will lose your consciousness for 40-60 minutes
C．your brain waves will show the delta rhythm
D．your brain waves will show the alpha rhythm