细胞的电学模型有哪些？

一个IPv6地址为21DA:0000:0000:0000:02AA :000F:FE08:9C5A，如果采用双冒号表示法，那么该IPv6地址可以简写为

A．0x21DA::0x2AA:0xF:0xFE08:0x9C5A

B．21DA::2AA:F:FE08:9C5A

C．0h21DA::0h2AA:0hF:0hFE08:0h9C5A

D．21DA::2AA::F::FE08::9C5A

《企业会计准则——固定资产》第十三条规定，确定固定资产成本时，应当考虑预计弃置费用因素。下列关于弃置费用的说法正确的有()。

A.一般企业的固定资产无须考虑弃置费用，只考虑处置费用。处置费用是净残值的组成部分

B.弃置费用仅针对特殊行业的特殊固定资产，例如石油天然气行业的油气资产、核电站的核燃料等。这些行业均承担了环保法规规定的环境恢复义务，且金额较大(可能大于相关固定资产的购建支出)

C.弃置费用需要考虑货币时间价值的影响且计算现值

D.所有企业的所有固定资产都需考虑弃置费用

E.弃置费用就是固定资产的清理费用

林地指生长乔木、竹类、灌木的土地，及沿海生长红树林的土地。包括迹地和居民点内部的绿化林木用地等。()

在一次国际会议上，来自四个国家的五位代表被安排坐在一张圆桌，为了使他们能够自由交谈，事先了解到情况如下：甲是中国人，还会说英语；乙是德国人，还会说汉语；丙是英国人，还会说法语；丁是日本人，还会说法语；戊是日本人，还会说德语，请问如何安排( )

A．甲丙戊乙丁

B．甲丁丙乙戊

C．甲乙丙丁戊

D．甲丙丁戊乙

Another critical factor that plays a part in susceptibility to colds is age. A study done by the University of Michigan School of Public Health revealed particulars that seem to hold true for the general population. Infants are the most cold-ridden group, averaging more than six colds in their first year. Boys have more colds than girls up to age three. After the age of three, girls are more susceptible than boys, and teenage girls average three colds a year to boys’ two.
The general incidence of colds continues to decline into maturity. Elderly people who are in good health have as few as one or two colds annually. One exception is found among people in their twenties, especially women, who show a rise in cold infections, because people in this age group are most likely to have young children. Adults who delay having children until their thirties and forties experience the same sudden increase in cold infections.
The study also found that economics plays an important role. As income increases, the frequency at which colds are reported in the family decreases. Families with the lowest income suffer about a third more colds than families at the upper end. Lower income generally forces people to live in more cramped quarters than those typically occupied by wealthier people, and crowding increases the opportunities for the cold virus to travel from person to person. Low income may also adversely influence diet. The degree to which poor nutrition affects susceptibility to colds is not yet clearly established, but an inadequate diet is suspected of lowering resistance generally.

The word "cramped" underlined in Paragraph 3 most probably means ______ .

A．cheap
B．crowded
C．depressing
D．simple