变性

设数列{a_n}是首相大于零的等比数列，则“a₁＜a₂”是“数列{a_n}是递增数列”的______条件．

依次填人下列横线上的词语，恰当的一组是(    )

①为什么某种生物的分布        而繁多，而它的邻种却分布得狭小而稀少呢?

②到了冬天，某些动物就要冬眠。冬眠并非死亡，而是一种新的          。

③红军“四渡赤水”一役，不仅扭转了长征以来的被动局面，而且大大地       了气焰嚣张的敌人。

A．普遍蜕化震动

B．广泛蜕化震慑

C．普遍退化震慑

D．广泛退化震动

慢性呼吸衰竭缺氧的典型表现是（）。

A.呼吸频率变慢

B.三凹征

C.发绀

D.头痛

E.肺性脑病

使用市场法评估机器设备，对市场的反映最为客观、能最精确地反映设备的市场价值的是（）。

A.直接比较法

B.因素调整法

C.成本比率调整法

D.综合估价法

Environmental problems are becoming more and more serious all over the world. For example, cars have made the air unhealthy for people to breathe and poisonous gas is given off by factories. Trees on the hills have been cut down and waste water is being poured continuously into rivers. Furthermore, wherever we go today, we can find rubbish carelessly disposed.

There are different kinds of pollutants, each of which comes from different sources. It is necessary to identify the source of pollution, in order to make a policy to eliminate them.

Different products, processes and activities of our industrialized world together form the major source of pollution. The forms of pollution can be mainly divided into three kinds—solid, liquid and gas.

These pollutions have greatly damaged our planet and continue to do so. In fact, pollution is threatening our existence. The whole ecological balance of the earth is changing. Massive destruction of environment has brought about negative effects and even posed a great threat to man’s existence.

We must face the situation that exists and take action to solve our environmental problems. For instance, new laws must be passed to place strict control over industrial pollution, the public must receive the education about the danger of pollution and so on.

The earth is our home and we have the duty to take care of it for ourselves and our later generation. Fortunately, more and more people have realized these problems. Measures have been taken to deal with these situations by the government. Laws have been passed to stop pollution, I hope the problems will be solved in the near future and our home will become better and better.

小题1: How many examples of environmental problems are given in the first paragraph?

A．2

B．3

C．4

D．5小题2: Which of the following is TRUE according to the passage?

A．In all there are three kinds of pollution

B．If people continue to pollute our planet, there will be no trees.

C．Industrial pollution has been completely controlled.

D．Laws have been passed to stop pollution and protect our environment.小题3: The sentence “We hope that all these measures will be effective and bring back a healthy environment” can best be put at the end of paragraph _____.

A．2

B．3

C．5

D．6小题4: The writer’s attitude towards the future of the earth is _____.

A．despair

B．negative

C．optimistic

D．hopeless