一般来说，前后所学的信息之间存在互相干扰。先前所学的信息对后面所学信息的干扰叫___

A person steps on what seems like solid ground but discovers with horror that the ground is giving way underfoot. The person struggles desperately but is trapped. There is no escape. Slowly the person sinks deeper and at last is gone. The solid ground was solid only in appearance. It was actually quicksand, which is a deep mass of fine sand mixed with water.

How is quicksand formed? Water pushes up from below the surface and is held by the sand. The grains of sand are forced apart by the water. They cannot hold any weight. The subsurface water may have come from a spring, a river, or a stream. Sometimes pools of water near beaches become filled with sand. When the soil under these pools does not allow for good drainage(排水), the sand can become stretches of quicksand.

Is it true that a person who steps into quicksand is doomed to die? No, for people have fought their way from quicksand to firm land again. It is panic(恐慌) that creates the condition that can result in death, for the more a person struggles, the worse matters become. Quick movements will make the sand yield for a time, but then it rushes back and settles solidly around the body.

People trapped in quicksand should either lie back with arms outstretched, or not move at all. When the weight of the sand around his body has displaced equals that person’s weight, the victim will stop sinking. With feet held still, and with slow movements of the arms, as in the backstroke(仰泳) in swimming, people have managed to roll to safety and reach firm ground.

小题1:Quick movements by a person trapped in quicksand will _______.

A．help the person reach firm ground

B．help prevent panic

C．make the same sand yield temporarily

D．make the sand hold the person’s weight小题2:Quicksand is _______.

A．a mass of fine sand mixed with water

B．formed only along rivers

C．found below subsurface water

D．solid ground小题3:Which statement does the article lead you to believe?

A．Stretches of quicksand are found only under the sea.

B．People should never try to escape from quicksand.

C．It is hard to keep calm if you fall into quicksand.

D．Only heavy people can be trapped in quicksand.小题4:The passage mainly tells about _______.

A．what solid ground looks like

B．the nature of quicksand

C．stepping into quicksand

D．escaping from quicksand

关于头颅侧位摄影的叙述，错误的是（）。

A.可用于了解蝶鞍的大小和形态

B.是头颅常规摄影位置

C.被检者取仰卧位

D.矢状面与床面平行

E.瞳问线与床面垂直

市场按买方的类型可分为消费市场和（）。

A．组织市场

B．信息市场

C．服务市场

D．产品市场

新海公司在依法取得营业执照后超过30日一直未向税务机关办理税务登记，税务机关了解该情况后，责令该公司限期改正。但是该公司逾期仍未改正，税务机关可以采取以下措施：

A．强制为其补办税务登记证

B．吊销其营业执照

C．核定其应纳税额，责令缴纳

D．认为其情节严重，移交司法机关，追究刑事责任

对于伴有急性肾衰的MODS病人，特别是循环不稳者进行血液净化治疗，一般主张首选

A．腹膜透析
B．间断血液透析(1HD)
C．单针血液超滤(SCUF)
D．血浆置换治疗
E．连续静脉-静脉血液滤过(CVVH)