The forest fire caused by the volcano is difficult to be______. A. put off B. put on

A.The fire reduced the forest to a few trees.

B.The big fire burnt the forest to a few trees.

C.The big fire burnt severl trees in the forest.

D.The fire made many trees burnt in the forest.

A.smell

B.spark

C.steam

D.smoke

Police and villagers unanimously __________the forest fire to thunder and lightning.

A.ascribed

B.approached

C.confirmed

D.confined

A. put off

B. put on

C. put out

D. put with

A．to blame for starting

B．to blame to start

C．to be blamed for starting

D．to blamed to start

A.By the means of…under the control

B.By means of…under control

C.By means of…under a control

D.By a means of…under control

The Smokey Bear(护林熊) fire prevention program has resulted in a savings of $20 billion on all federal(联邦的), state and private forested land(私有林地). In 1941, 208,000 forest fires burned 30 million acres, while in 1981, fewer than 165,000 fires burned about three million acres. While forest usage has increased, the proportion(比例) of human-caused fires has remained stable; people still cause nine out of ten forest fires. But the biggest cause of fires is arson(纵火), accounting for(引起) 34 percent of forest fires in 1981.

1. According to the passage, use of forested land has ____.

A、stabilized

B、been privatized

C、decreased

D、risen

2. According to the passage, in 1941 forest fires burned ____.

A、less acres than in 1981

B、3 million acres

C、ten times as many acres as in 1981

D、20 million acres more than in 1981

3. According to the passage, the number of human-caused fires ____.

A、has remained the same proportionately

B、has increased

C、is the same as the arson cases

D、accounts for 34 per cent of forest fires

4. According to the passage, which of the following statements is true？

A、Nine out of ten fires are caused by arsonists.

B、The Smokey Bear program has saved the nation a lot of money.

C、There are more forest fires now than before.

D、People do not use the forests as much as they did in the past.

5. It may be inferred from the passage that ____.

A、the majority of fires are caused by humans

B、arson is increasing every year

C、more acres are destroyed by fire each year

D、fewer people are using the forests

27____was 25 times more deadly than normal and it caused more deaths than the First World War.

The consequences of a massive 28____could be disastrous for 29____.For example, a cloud of ash could 30_the sun and the molten lava would destroy everything in its path.

26. A. virus B. chemical C. epidemic D. wave

27. A. impact B. disaster C. pandemic D. eruption

28. A. forest fire B. tsunami C. greenhouse gas D. volcanic eruption

29. A. terrorists B. scientists C. humanity D. mass migration

30. A. block out B. head for C. put out D. wipe out

ity on Earth. In terms of man's brief life it appears permanent and unchanging, save for the seasonal growth and fail of the leaves, but to forester it represents the climax of a long succession of events.

No wooded landscape we see today has been forest for all time. Plants have minimum requirements of temperature and moisture and, in ages past, virtually every part of Earth's surface has at some time been either too dry or too cold for plants to survive. However, as soon as climatic conditions change in favor of plant life, a fascinating sequence of changes occurs, called a primary succession.

First to colonize the barren land are the lowly lichens, surviving on bare rock. Slowly, the acids produced by these organisms crack the rock surface, plant debris accumulates, and mosses establish a shallow root-hold. Ferns may follow and, with short grasses and shrubs, gradually form. a covering of plant life. Roots probe even deeper into the developing soil and eventually large shrubs give way to the first trees. These grow rapidly, cutting off sunlight from the smaller plants, and soon establish complete domination-closing their ranks and forming a climax community which may endure for thousands of years.

Yet even this community is not everlasting. Fire may destroy it outright and settlers may cut it down to gain land for pasture or cultivation. If the land is then abandoned, a secondary succession will take over, developing much faster on the more hospitable soil. Shrubs and trees are among the early invaders, their seeds carried by the wind, by birds and lodged in the coats of mammals.

For as long as it stands and thrives, the forest is a vast machine, storing energy and many elements essential for life.

What does the forest strike mankind as permanent？

A．The trees are in community.

B．The forest is renewed each season.

C．Man's life is short in comparison.

D．It is an essential part our lives.