样本数据“１,２,３,４,５,６,７”的标准差等于 （用数字作答）。

某旅游团一行15人抵达杭州，地陪小王在客人进住饭店之后，开始与领队商定第二天的日程安排。小王发现领队所持日程第二天是去千岛湖，而自己的计划是杭州市区活动，且无千岛湖的活动安排。这时地陪小王应（）。

A．婉言谢绝，说明我方不便单方面违反合同

B．向领队做详细解释说明工作，并设法将其说服

C．按照领队所持的计划活动，但应事先向领队说明，要按规定收取杭州至千岛湖的超公里费及门票费用。

D．及时报告旅行社，查明原因，分清责任

26．To our great joy, it snowed_______ the night of Feb．14 this year in Shanghai, arousing the curiosity of the residents．

A．in

B．for

C．at

D．On

一颗人造地球卫星绕地球做匀速圆周运动，卫星离地面的高度为h．已知地球半径为R，地面重力加速度为g．求：

（1）卫星的线速度；

（2）卫星的周期．

In ancient Greek, the term euthanatos meant "easy death". Today euthanasia (安乐死) generally refers to mercy killing, the voluntary (自愿) ending of the life of someone who is terminally ill. Like abortion, euthanasia has become a legal, medical, and moral issue over which opinion is divided.

Euthanasia can be either active or passive. Active euthanasia means that a physician or other medical personnel takes an action that will result in death, such as giving an overdose of deadly medicine. Passive euthanasia means letting a patient die for lack of treatment, or stopping the treatment that has begun. Examples of passive euthanasia include taking patients off a breathing machine or removing other life-support systems. Stopping the food supply is also considered passive.

A good deal of the debate about mercy killing originates from the decision-making process. Who decides whether a patient is to die This issue has not been solved legally in the United States. The matter is left to state law, which usually allows the physician in charge to suggest the option of death to a patient’s relatives, especially if the patient is brain dead. In an attempt to make decisions about when their own lives should end, several terminally ill patients in the early 1990s used a controversial suicide device, developed by Dr. Jack Kevorkian, to end their lives.In parts of Europe, the decision-making process has become very flexible. Even in cases where the patients are not brain dead, patients have been put to death without their approval at the request of relatives or at the suggestion of physicians. Many cases of passive euthanasia involve old people or newborn infants. The principle justifying this practice is that such individuals have a "life not worthy of life".In countries where passive euthanasia is not legal, the court systems have proved very tolerant in dealing with medical personnel who practice it. In Japan, for example, if physicians follow certain guidelines they may actively carry out mercy killings on hopelessly ill people. Courts have also been somewhat tolerant of friends or relatives who have assisted terminally ill patients to die.

The attitude of the writer toward euthanasia is ().

A. negative

B. positive

C. objective

D. casual

关于经纬线的叙述，正确的是（）

A．以0º经线为界，东经和西经的度数分别向东、向西越来越小

B．经线指示东西方向，纬线指示南北方向

C．以赤道为界，北纬和南纬的度数分别向北、向南越来越大

D．所有经线都是大小相等的圆，而所有纬线是大小不等的圆