若数据A持有事务T1所加的排它锁，那么其他事务对数据A（）。 A．加共享锁成功，加排

氧含量是指（）.

A.Hb结合的O₂量

B.物理溶解O₂量

C.血液与大气接触后，Hb与O₂结合的量

D.循环过程中，血液释放给组织的O₂量

E.隔绝空气条件下，血液中实际的含O₂量

咖啡因的药理作用为

A．兴奋大脑皮层

B．兴奋延髓呼吸中枢

C．增加心肌收缩力

D．增加脑血流

E．收缩支气管平滑肌

阅读理解.

     What exactly are white lions?"They are a color variation of regular lions,"says William

Swanson,director of animal research at the Cincinnati Zoo,in Ohio.

     White lions are the result of a rare color gene mutation(变异)．When both a male and

a female lion carry the same white genes,there is a good chance that one or more of their

cubs(幼兽)will be born with white fur.

     Not many lions carry the white mutation.In nature,it's rare.A mutation can make an

animal's survival more difficult.For example,being white makes it harder for the animal to

mix with its surroundings.Mutations also can cause physical problems,so those animals

generally do not survive long enough to reproduce.

     But sometimes white lion cubs are born among wild lions,especially in two areas of

South Africa.

     In 1975 two white cubs were spotted in the wild in South African reserve.They were

seized and sent to a zoo.Today about 500 cubs of those two white lions and a few others

known to have the white color gene live around the world in zoos,circuses,farms and private

preserves.

      White lions may be extremely rare in the wild,but breeders(饲养动物的人)know how

to create more of them.This has created serious concern and debate.

      White lions continue to exist only because they are inbred by people-fathers and

daughters,sisters and brothers.Scientists worry that it also will cause health issues for white

lions.

     Inbreeding to create white lions as moneymaking attractions is only one concern.Another

concern is that some people want to release captive－bred(人工繁殖的)white lions into

the wild in South Africa to restore balance to the ecosystem.However,not everyone agrees

that releasing these white lions into the wild is a good idea.Dan York of Hillsdale College

has been studying white lion genetics and is worried.He says that because so many of today's

white lions are inbred,it could spread health problems.If they breed with wild lions,they'll

pass on the genetic problems to the wild population.

     Instead of releasing captive－bred white lions,York suggests that South Africa concentrate

on protecting all of its wild lions.That would ensure the safety of the wild population of lions,

which may produce healthy white cubs in the future.

1．It'sdifficultforawhiteliontosurvivebecause__________.

a．itsfurcontrastssharplywiththesurroundings

b．themutationmaycausephysicalproblems

c．itislikelytobeattackedbywildlions

d．itishuntedbyhumanbeings

A．a,b　　　　　　　

B．a,d

C．a,c

D．b,d

2．What does the underlined word "inbred" in Paragraph 7 probably mean?

A．kept in enclosed space and unable to run away

B．bred in human－controlled environments with restricted settings

C．produced by breeding among closely related members

D．born among wild lions and kept in the zoo

3．One of the reasons for inbreeding white lions is that __________.

A．they can bring people a profit

B．their fur can be of great use

C．people want to keep white lions as pets

D．people want to study the genes of white lions

4．Which of the following agrees with Dan York's opinion?

A．It's useless studying white lion genetics.

B．White lion cubs born among wild lions are more healthy than captive－bred ones.

C．White lions shouldn't be kept in zoos or circuses.

D．The ecosystem in South Africa is being seriously damaged.

5．It can be inferred from the passage that __________.

A．white lions are seldom seen in the wild

B．color gene mutation is common among lions

C．South Africa is taking strict measures to protect its wild lions

D．white lions will disappear from the earth soon

2001年元月，甲、乙、丙共同设立一合伙企业。合伙协议约定：甲以现金人民币5万元出资，乙以房屋作价人民币8万元出资，丙以劳务作价人民币4万元出资；各合伙人按相同比例分配盈利、分担亏损。合伙企业成立后，为扩大经营，于2001年6月向银行贷款人民币5万元，期限为1年。2001年8月，甲提出退伙，鉴于当时合伙企业盈利，乙、丙表示同意；同月， 甲办理了退伙结算手续。2001年9月，丁入伙。丁入伙后，因经营环境变化，企业严重亏损。 2002年5月，乙、丙、丁决定解散合伙企业，并将合伙企业现有财产价值人民币3万元予以分配，但对未到期的银行贷款未予清偿。2002年6月，银行贷款到期后，银行找合伙企业清偿债务，发现该企业已经解散，遂向甲要求偿还全部贷款。甲称自己早已退伙，不负责清偿债务。银行向丁要求偿还全部贷款，丁称该笔贷款是在自己入伙前发生的，不负责清偿。银行向乙要求偿还全部贷款，乙表示只按照合伙协议约定的比例清偿相应数额。银行向丙要求偿还全部贷款，丙则表示自己是以劳务出资的，不承担偿还贷款义务。
请回答下列问题：
(1)甲、乙、丙、丁各自的主张能否成立说明理由。
(2)合伙企业所欠银行贷款应如何清偿说明理由。
(3)在银行贷款清偿后，甲、乙、丙、丁内部之间应如何分担清偿责任说明理由。

墙根（远离墙角）处声源的指向性因数Q=（）。

A、1；

B、2；

C、4；

D、8。