根据总账与明细账的平行登记要求，每项经济业务必须在同一天登记明细账和总账。( )

压缩机不能启动的原因及处理。

所谓“预后”是指根据经验预测疾病的发展情况，对疾病结局的预先估计。通常以治愈率、复发率、缓解率、病残率、病死率和生存率等概率指标表示。
根据以上定义，下面哪种情况属于预后( )

A．甲医生通过已掌握的白血病的转归与结局的发生概率及相应的影响因素，认定某一白血病患者极有可能恢复健康
B．乙老太太曾是一名文艺工作者，近段时间经常肝区疼痛，便认定自己得了肝癌，将不久于人世
C．丙医生邻居之于目视无神，精神不振，形体消瘦，判断其患了重病或症
D．丁先生路遇一醉酒之人，遭其殴打，据其以往经验确定为轻微伤

旋塞阀具有结构简单，外形尺寸小，（）等优点。缺点是密封面容易磨损，启闭用力较大。

A、启闭迅速和密封性能好

B、启闭缓慢和密封性能好

C、启闭迅速和密封性不好

D、启闭缓慢和密封性能不好

南京中山陵、北京颐和园、北京中山公园分别属于( )。

A．规则式园林、混合式园林、自然式园林
B．规则式园林、自然式园林、混合式园林
C．混合式园林、规则式园林、自然式园林
D．自然式园林、混合式园林、规则式园林

All animals must rest, but do they really sleep as we know it The answer to this question seems obvious. If an animal regularly stops its activities and stays quiet and unmoving—if it looks as though it is sleeping—then why not simply assume that it is in fact sleeping But how can observers be sure that an animal is sleeping

They can watch the animal and notice whether its eyes are open or closed, whether it is active or lying quietly, and whether it responds to light or sound. These factors are important clues, but they often are not enough. Horses and cows, for example, rarely close their eyes, and fish and snakes cannot close them. Yet this does not necessarily mean that they do not sleep. Have you ever seen a cat dozing with an eye partly open Even humans have occasionally been observed to sleep with one or both eyes partially open. Animals do not necessarily lie down to sleep either. Elephants, for example, often sleep standing up, with their tusks resting in the fork of a tree. Finally, while "sleeping" animals often seem unaware of changes in the sounds and light and other stimuli around them, that does not really prove they are sleeping either.

Observations of animal behavior alone cannot fully answer the question of whether or not animals sleep. The answers come from doing experiments in "sleep laboratories" using a machine called the electroencephalograph (EEC). The machine is connected to animals and measures their brain signals, breathing, heartbeat, and muscle activity. The measurements are different when the animals appear to be sleeping than when they appear to be awake. Using the EEC, scientists have confirmed that all birds and mammals studied in laboratories do sleep. There is some evidence that reptiles, such as snakes and turtles, do not truly sleep, although they do have periods of rest each day, in which they are quiet and unmoving. They also have discovered that some animals, like chimpanzees, cats, and moles (who live underground), are good sleepers while others, like sheep, goats, and donkeys, are poor sleepers. Interestingly, the good sleepers are nearly all hunters with resting places that are safe from their enemies. Nearly all the poor sleepers are animals hunted by other animals: they must always be watching for enemies, even when they are resting.

According to the research findings mentioned in the passage, reptiles（）

A. such as turtles and snakes cannot close their eyes

B. cannot be studied with an EEC

C. do not sleep in the true sense of the word

D. do not need to rest