当事人一方在施工合同履行过程中不承担违约责任的是( )。A．因为三通一平工期拖延，

18世纪中英正常贸易中，中国始终处于出超地位。出现这种情况的根本原因是(    )

A．中国的产品优于英国的

B．中国占有统治地位的自然经济

C．清政府实行闭关锁国政策

D．其他国家产品冲击了英在华的市场

防止金属腐蚀，特别是钢铁的锈蚀是世界科学研究和技术领域中的重大问题．某同学为了探究铁生锈与哪些因素有关，设计了一个实验（如图所示）：该同学找到三个铁钉，经过酸洗除锈、干燥后，分别放入A、B、C三支试管中；再向A、B试管中各注入煮沸后迅速冷却的蒸馏水，A中的铁钉部分浸入水中，B中的铁钉浸没水中，并在水面上注入一层植物油；C中放入一团裹有干燥剂

CaCl₂的棉花并塞上橡皮塞．请你和该同学一起回答下列问题：

（1）写出一个酸洗除锈（铁锈的主要成分是Fe₂O₃）反应的化学方程式：______．

（2）在三支试管中，容易生锈的是______中的铁钉．因此铁生锈的条件是______．

（3）为了防止铁制品生锈，应采取的措施是：______（写出一种）．

河南大学软件学院位于郑州市。

旅游质量监督所受理赔偿案件，应当自受理之日起（）天内审理终结，有特殊原因的，经上级质量监督所批准，可以延长审理（）日。

A.90，30

B.30，45

C.45，90

D.60，30

The topic of cloning has been a politically and ethically controversial one since its very beginning. While the moral and philosophical aspects of the issues are entirely up to the interpretation of the individual, the application of cloning technology can be studied objectively. Many in the scientific community advocate the use of cloning for the preservation and support of endangered species of animals, which aside from cloning, have no other practical hope for avoiding extinction.

The goal of the use of cloning to avoid extinction is the reintroduction of new genes into the gene pool of species with few survivors, ensuring the maintenance and expansion of genetic diversity. Likely candidates for this technique are species known to have very few surviving members, such as the African Bongo Antelope, the Sumatran Tiger, and the Chinese Giant Panda. In the case of Giant Panda, some artificial techniques for creating offspring have already been performed, perhaps paving the way for cloning as the next step in the process.

With the estimated population of only about 1000 Giant Pandas left in the world, the urgency of the situation has led to desperate measures. One panda was born through the technique of artificial insemination in the San Diego Zoo in the United States. "Hua Mei" was born in 1999 after her parents, Hsing-Hsing and Ling-Ling, had trouble conceiving naturally.

The plan to increase the Giant Panda population through the use of cloning involves the use of a species related to the Giant Panda, the American Black Bear. Egg cells will be removed from female black bears and then fertilized with Panda cells such as those from Ling-Ling or Hsing-Hsing. The fertilized embryo will then re-implanted into the black bear, where it will grow and mature, until a new panda is delivered from the black bear host.

Critics of cloning technology argue that the emphasis on cloning as a method by which to preserve species will draw funding away from other methods, such as habitat preservation and conservation. Proponents of cloning counter that many countries in which many endangered species exist are too poor to protect and maintain the species’ habitats anyway, making cloning technology the only practical way to ensure that those species survive to future generations. The issue is still hotly debated, as both sides weigh the benefits that could be achieved against the risks and ethical concerns that constantly accompany any argument on the issue. (402 words)

Notes: ethically 道德上。gene pool 基因库。insemination n.受精。fertilize 使受精。embryo 胚胎。proponent支持者，拥护者。weigh A against B权衡A和B的利弊。

The author directs attention to "Hua Mei", the baby panda born in the San Diego Zoo, in order to（）

A. show that cloning as an artificial birth technique has succeeded

B. argue that pandas are a particularly likely candidate for cloning

C. show that artificial birth techniques other than cloning have succeeded

D. demonstrate the necessity of cloning and other artificial birth techniques to the survival of certain species