普通胶带输送机倾斜向上输送物料时，不同粉粒料所允许的最大倾角一般为16°-20°。

某数据库中有表Tabk_Goods(GoodsID，GoodsClassID，GoodsName，SaleUnitPrice)和表Table_GoodsClass(GoodsClassID，GoodsClassName)，对家用电器类商品进行分类显示，如果商品的单价(SaleUnitPrice)高于3000，则显示’高档商品’；如果单价在1000～3000之间，则显示’中档商品’；如果单价低于1000，则显示’低档商品’。完成下列的SQL语句。
SELECT GoodsName，SaleUnitPrice，Type=
CASE
______
______
______
END
FROM ______
ON______
WHERE GoodsClassName=’家用电器’

对面神经的解释下列哪项错误（）

A.主管面部表情肌的运动

B.损伤后可有面部感觉障碍

C.主管舌前2/3味觉

D.感觉神经纤维为鼓索纤维

E.损伤后表现为周围性面瘫

能分泌抗体的是（）。

A.淋巴细胞

B.小鼠脾细胞

C.小鼠骨髓细胞

D.小鼠骨髓瘤细胞

E.杂交细胞

男性，30岁，交通事故被压伤，伤后2小时被抬入院，严重下肢挤压伤合并骨折和严重低血压，此时首要处理应该是（）

A.注射止痛剂

B.输血和补液

C.骨折固定

D.应用血管收缩药，以提高血压

E.吸氧

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 author, all animals（）

A. spend some time resting

B. close their eyes when sleeping

C. are good sleepers

D. are poor sleepers