类之间共享属性和操作的机制称为 (1) 。一个对象通过发送 (2) 来请求另一个对象

阅读理解。

     Our climate is changing around the world. Because of man-made pollution, the earth is becoming warmer

and warmer. The 1990s were the warmest ten years and the 20th century was the warmest century.

     There are many signs of the climate change around us. In Europe, the glaciers (冰川) of the Alps are

disappearing and the droughts in the Mediterranean are worse than before. Southern Spain is turning into

desert. And, as ice melts, sea levels all over the world are rising.

     We are in danger because it will rain less because of the hot weather. In Southeast England there used

to be much rain. but the amount of rain will drop by half in the next 40 years. Fewer people may die from

cold in winter. but many more could die from heat in summer. In the summer of 2003, about 20,000 people

died from heat in France and soon happened in Britain.

1. What makes the earth warmer and warmer?

A. The waste of water.

B. The heat of summer.

C. The heavy rain.

D. Man-made pollution.

2. Which is one of the signs of the climate change?

A. The number of people in the world is growing.

B. There is more snow than before.

C. There isn't much water as before in the Mediterranean.

D. It is very cold in winter.

3. What can cause the rise of sea levels?

A. The melting of ice.

B. The reducing of rain.

C. The cold weather.

D. The strong wind.

4. When win the amount of rain in Southeast England drop by half?

A. Next year.

B. Two years later.

C. In the next thirty years.

D. In the next forty years.

5. This passage is mainly about the _______.

A. change of climate

B. disappearance of glaciers

C. pollution of the air

D. droughts in the Mediterranean

书面表达。

      人类只有一个地球。根据提示，以“Saving the Earth”为题，写一篇80词左右的短文。

      提示：

      1. 如何保护环境已成为世界最大难题之一； 

      2. 各种污染破坏环境，损害健康；

      3. 不要乱倒垃圾，乱排废水； 

      4. 我们应该保护环境，使我们的家园更加美丽。

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一批货物共w吨，搬运工每小时搬a吨，t小时后，还剩下______吨．

磨耗的生理意义不包括（）

A.有利于平衡的建立

B.降低牙尖高度

C.协调临床冠根比例

D.形成反横曲线

E.邻面持续磨耗，防止前牙拥挤

早产儿，体重2.2kg，生后2天诊断为新生儿溶血病。化验胆红素342μmol/L，出现嗜睡、拥抱反射消失，肌张力减低。

首选的治疗是（）

A.光照治疗

B.换血疗法

C.输白蛋白

D.纠正酸中毒

E.给予苯巴比妥