蓝氏贾第鞭毛虫病原学检查，粪便检查，急性期取新鲜标本做（）（水样稀便）。慢性期成形粪

晴天，在茂密的树林下面，阳光透过树叶的缝隙，会在地上留下许多圆形的光斑，这是由于 ________________________________ 的原理．那么在发生日偏食的短暂时间里，地上的光斑是怎样的？请在下图所示的形状中选择出一个光斑的示意图________．

女性，24岁。5小时前骤起腹泻，稀便转水样便，排便15次，量多，呕吐3～4次来诊。无发热、腹痛。病前在舟山旅游。体检：脉搏102次／min，BP8／5.3kPa（60／40mmHg），眼球稍下陷，腹部无压痛，大便光镜检：WBC0～2／HP，RBC0～1／HP，拟诊为副霍乱。

本例抗菌治疗的首选药物是（）。

A.氯霉素

B.呋喃唑酮

C.四环素

D.SMZ加TMP

E.多西环素（强力霉素）

The following questions present a sentence, part of which or all of which is underlined. Beneath the sentence you will find five ways of phrasing the underlined part. The first of these repeats the original; the other four are different. If you think the original is best, choose the first answer; otherwise choose one of the others.

These questions test correctness and effectiveness of expression. In choosing your answer, follow the requirements of standard written English; that is, pay attention to grammar, choice of words, and sentence construction. Choose the answer that produces the most effective sentence; this answer should be clear and exact, without awkwardness, ambiguity, redundancy, or grammatical error.

While the new health insurance regulations may be onerous for large corporations, it can potentially be disastrous for small business owners, who in many cases will have to lay off employees in order to pay for the extended coverage.（）

A. it can potentially be disastrous for small business owners, who

B. they are potential disasters for small business owners, since

C. potentially they will be disastrous for small business owners, whom

D. for small business owners it is a potential disaster, because

E. they are potentially disastrous for small business owners, who

第一个点燃奥林匹克圣火的女性是哪个国家的？

在OSI七层结构模型中，处于数据链路层与传输层之间的是 ( )

A．物理层

B．网络层

C．会话层

D．表示层