多发性骨髓瘤可出现（） A.甲胎蛋白（AFP）阳性 B.癌胚抗原（CE A.阳性 C

将命题“同角或等角的补角相等”写成：如果______，那么______．

一建筑工地20位民工晚餐后集体发病，陆续出现恶心、呕吐、呼吸困难而入急诊室。体检发现患者口唇均中-重度发绀。

最可能的诊断是（）

A.CO中毒

B.有机磷中毒

C.亚硝酸盐中毒

D.工业酒精中毒

E.地西泮中毒

腋毛癣与下列哪种感染有关（）。

A.花斑癣菌

B.糠秕孢子菌

C.红色毛癣菌

D.毛囊虫

E.纤细棒状杆菌

下列是有关我国产业结构状况的材料：
材料1
我国每亩耕地占有农机总动力只有0.16千瓦，远远低于发达国家水平……机播和机收面积均不超过20%……在现有耕地中，2/3是中低产田，目前改造的步伐仍然比较慢。
摘自1997年1月11日《经济日报》
材料2
1996年工业产销衔接水平虽然逐季提高，但全年产销率仍比正常水平低1～2个百分点；产品积压，资金拖欠未见缓解，年末产成品资金占用比年初增加750多亿元，应收帐款净额增加1200多亿元、企业亏损比较严重，亏损面达到23%。
摘自《国家统计局关于1996年国民经济和社会发展的统计公报》
材料3
据专家估计，科技在农业中的贡献率如能提高至50%，则我国的粮食生产能力可提高4500万吨。
摘自1997年4月1日《经济日报》
“对那些长期亏损、资不抵债而又扭亏无望的国有企业，按法定程序实施破产清算，既是加速结构调整的重要途径，也是保护债权人利益；主要是国有银行资产，免受更大损失的积极措施。”
摘自1997年4月21日《人民日报》评论员文章
请回答：
(1)根据材料1、材料2，说明目前我国产业结构存在的主要问题。
(2)对材料2反映出的问题，分析其形成的主要原因是什么
(3)材料3表明我国加快产业结构调整的措施是什么
(4)结合全部材料，指出我国实现产业结构合理化应遵循的方针是什么

Birds that are half-asleep — with one brain hemisphere (半球) alert(警觉) and the other sleeping — control which side of the brain remains awake, according to a new study of sleeping ducks.

Earlier studies have recorded half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once.

Decades of studies of bird groups led researchers to predict extra alertness in the end-of-the-row sleepers which tend to be attacked more easily. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze(注视) direction.

Also, birds napping (打盹) at the end of the line depend on single-hemisphere sleep, rather than total relaxation, more often than inner ducks did. Turning 16 birds through the positions in a four-duck row, the researchers found that compared with 12 percent for birds in inner spots, outer birds half-asleep during some 32 percent of napping time.

“We believe this is the first evidence for an animal behaviorally controlling sleep and wakefulness at the same time in different regions of the brain,” the researchers say.

The results provide the best evidence for a long-standing assumption that single-hemisphere sleep developed over time as creatures scanned for enemies. The preference for opening an eye on the lookout side could be widespread, he predicts. He’s seen it in a pair of birds napping side-by-side in the zoo and in a single pet bird sleeping by a mirror. The mirror-side eye closed as if the reflection were a companion and the other eye stayed open.

Useful as half-sleeping might be, it’s only been found in birds and such water animals as dolphins, whales, and seals. Perhaps keeping one side of the brain awake allows a sleeping animal to surface occasionally to avoid drowning.

Studies of birds may offer unique insights into sleep. Jerome M. Siegel of the UCLA says he wonders if birds’ half-brain sleep “is just the tip of the iceberg.” He supposes that more examples may turn up when we take a closer look at other species.

小题1:According to the passage, birds often half sleep because ______.

A．they have to watch out for possible attacks

B．their brain hemispheres take turns to rest

C．the two halves of their brain are differently organized

D．they have to constantly keep an eye on their companions小题2:What is implied about the example of a bird’s sleeping in front of a mirror?

A．An imagined companion gives the bird a sense of security.

B．Birds prefer to sleep in pairs for the sake of their security.

C．The phenomenon of birds napping in pairs is widespread.

D．A single pet bird enjoys seeing its own reflection in the mirror.小题3:It can be inferred that _______.

A．Birds never sleep with both hemispheres resting at once.

B．Inner ducks depend on single-hemisphere sleep, rather than total relaxation, as often as birds napping at the end of the line do

C．It is not the first time for scientists to research on birds’ half-brain sleep

D．Birds hardly sleep without a companion小题4:By saying “just the tip of the iceberg”, Siegel suggests that _______.

A．half-brain sleep has something to do with icy weather

B．the mystery of half-brain sleep is close to being solved

C．most birds living in cold regions tend to be half sleepers

D．half-brain sleep may exist among other species