Many people believe the glare from snow causes snow-blindness． Yet, dark glasses or not,they find themselves suffering from headaches and watering eyes, and even snow-blindness, when exposed to several hours of "snow light"．The United States Army has now determined that glare from snow does not cause snow-blindness in troops in a snow-covered country． Rather, a man's eyes frequently find nothing to focus on in a broad expanse of barren snow-covered terrain． So his gaze continually shifts and jumps back and forth over the entire landscape in search of something to look at． Finding nothing,hour after hour, the eyes never stop searching and the eyeballs become sore and the eye musclesache． Nature offsets this irritation by producing more and fluid which covers the eyeball． The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result istotal, even though temporary, snow-blindness．Experiments led the Army to a simple method of overcoming this problem． Scouts ahead of a main body of troops are trained to shake snow from evergreen bushes, creating a dotted line as they cross completely snow-covered landscape． Even the scouts themselves throw lightweight, dark colored objects ahead on which they too can focus． The men following can then see something．Their gaze is arrested． Their eyes focus on a bush and having found something to see, stop scouring the snow-blanketed landscape． By focusing their attention on one object at a time, the men can cross the snow without becoming hopelessly snow-blind or lost． In this way the problem of crossing a solid white terrain is overcome．?When the eyes are sore tears are produced to
A.clear the visionB.remedy snow-blindnessC.ease the irritationD.loosen the muscles

Much of the debate on an ongoing society in China has focused on the extended families__________ the number of "empty-nets" is growing by the millions every year．
A.thatB.whenC.whereD.which

Many people believe the glare from snow causes snow-blindness． Yet, dark glasses or not,they find themselves suffering from headaches and watering eyes, and even snow-blindness, when exposed to several hours of "snow light"．The United States Army has now determined that glare from snow does not cause snow-blindness in troops in a snow-covered country． Rather, a man's eyes frequently find nothing to focus on in a broad expanse of barren snow-covered terrain． So his gaze continually shifts and jumps back and forth over the entire landscape in search of something to look at． Finding nothing,hour after hour, the eyes never stop searching and the eyeballs become sore and the eye musclesache． Nature offsets this irritation by producing more and fluid which covers the eyeball． The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result istotal, even though temporary, snow-blindness．Experiments led the Army to a simple method of overcoming this problem． Scouts ahead of a main body of troops are trained to shake snow from evergreen bushes, creating a dotted line as they cross completely snow-covered landscape． Even the scouts themselves throw lightweight, dark colored objects ahead on which they too can focus． The men following can then see something．Their gaze is arrested． Their eyes focus on a bush and having found something to see, stop scouring the snow-blanketed landscape． By focusing their attention on one object at a time, the men can cross the snow without becoming hopelessly snow-blind or lost． In this way the problem of crossing a solid white terrain is overcome．To prevent headaches, watering eyes and blindness caused by the glare from snow, dark glasses are__________ ．
A.indispensibleB.usefulC.ineffectiveD.available

The function of the sentence "A nice day, isn't it? " is__________ ．
A.informativeB.phaticC.directiveD.performative

Many people believe the glare from snow causes snow-blindness． Yet, dark glasses or not,they find themselves suffering from headaches and watering eyes, and even snow-blindness, when exposed to several hours of "snow light"．The United States Army has now determined that glare from snow does not cause snow-blindness in troops in a snow-covered country． Rather, a man's eyes frequently find nothing to focus on in a broad expanse of barren snow-covered terrain． So his gaze continually shifts and jumps back and forth over the entire landscape in search of something to look at． Finding nothing,hour after hour, the eyes never stop searching and the eyeballs become sore and the eye musclesache． Nature offsets this irritation by producing more and fluid which covers the eyeball． The fluid covers the eyeball in increasing quantity until vision blurs, then is observed, and the result istotal, even though temporary, snow-blindness．Experiments led the Army to a simple method of overcoming this problem． Scouts ahead of a main body of troops are trained to shake snow from evergreen bushes, creating a dotted line as they cross completely snow-covered landscape． Even the scouts themselves throw lightweight, dark colored objects ahead on which they too can focus． The men following can then see something．Their gaze is arrested． Their eyes focus on a bush and having found something to see, stop scouring the snow-blanketed landscape． By focusing their attention on one object at a time, the men can cross the snow without becoming hopelessly snow-blind or lost． In this way the problem of crossing a solid white terrain is overcome．Snow-blindness may be avoided by__________
A.concentrating to the solid white terrainB.searching for something to look at in snow-covered terrainC.providing the eyes with something to focus onD.covering the eyeballs with fluid

The text is approachable, coping well with quite__________subjects．
A.complexB.complicatedC.sophisticatedD.intricate

提出现代生物-心理-社会医学模式是（）

A.恩格尔B.波特C.托马斯·帕茨瓦尔D.比彻尔E.桑德斯

付款人在进行付款时无（）

A.形式审查义务

B.实质审查义务

C.附带审查义务

D.票据外有关事项的审查义务

根据《公司法》的规定,有限责任公司下列人员中,可以提议召开股东会临时会议的是()。
A.总经理B.人数过半数的股东C.监事会主席D.人数为半数的董事

关于股份有限公司中的监事会，下列说法错误的是()

A.监事会负责提议聘请或更换外部审计机构B.监事会主席和副主席由全体监事过半数选举产生C.监事会中的职工代表的比例不得低于三分之一D.监事会应至少每6个月召开一次会议

三北精神的科学内涵