1 . 阅读下面材料，在空白处填入适当的内容(1个单词)或括号内单词的正确形式。

Food from the air

Everyone has seen plants growing, but have you ever thought     1     they get their food? In the seventeenth century, a European scientist     2     (call) Van Helmot asked this question. Like most people, he thought that plants must get their food from soil. However, Van Helmot decided       3     (test) the theory with experiments.

First, he dried some soil, put it into a pot and weighed it. Next, he weighed a small tree, planted it in the pot and added rain water. Then, he watered it     4     (regular) with rain water.

After five years, he removed the tree from the pot and weighed it again. He found that the tree had gained     5     huge amount of weight. When he weighed the soil, however, it was almost exactly the same as it had been five years    6    . So Van Helmot drew the    7    (conclude) that the tree grew by drinking water. Though it turned out to be wrong, he showed the importance of the use of scientific evidence to support ideas.

We now know that plants and trees make their own food. Their leaves, when exposed     8     the air and sun, are like factories    9     can change the energy from the sun into chemical energy. During this process (过程), oxygen and sugar     10     (produce). The oxygen is released back into the air, and the sugar is used by the plant as food.

2 . With no special equipment, no fences and no watering, two abandoned agricultural fields in the UK have been rewilded (重新野化), in large part due to the efforts of jays, which actually “engineered” these new woodlands. Researchers now hope that rewilding projects can take a more natural and hands-off approach and that jays can shed some of their bad reputations.

The two fields, which researchers have called the New Wilderness and the Old Wilderness, had been abandoned in 1996 and 1961 respectively. The former was a bare field, while the latter was grassland—both lay next to ancient woodlands. Researchers had suspected that the fields would gradually return to wilderness, but it was impressive to see just how quickly this happened, and how much of it was owed to birds.

Using aerial data, the researchers monitored the two sites. After just 24 years, the New Wilderness had grown into a young, healthy wood with 132 live trees per hectare, over half of which (57%) were oaks. Meanwhile, the Old Wilderness resembled a mature woodland after 39 years, with 390 trees per hectare.

“This native woodland restoration was approaching the structure (but not the species composition) of long-established woodlands within six decades,” the researchers explained in the study.

Part of this reforestation was done by the wind, and researchers suspect that previous ground disturbance may have aided the woodland establishment—which is good news, as it would suggest that agricultural areas may be reforested faster than anticipated. However, animals—Eurasian jays, thrushes, wood mice, and squirrels—also played an important role in helping the forests take shape. This handful of species provided much of the natural regeneration needed for the forest to develop. Jays, in particular, seem to have done a lot of heavy lifting.

1. What does the underlined word “shed” in Paragraph 1 refer to?

A．Be opposed to.

B．Be ashamed of.

C．Get used to.

D．Get rid of.

2. Which aspect of the changes in the two fields impressed the researchers?

A．The scale of the woodlands.

B．The diversity of the fields.

C．The rate of the changes.

D．The frequency of the wilderness.

3. What does the author want to tell us by providing some data in Paragragh 3?

A．The woodland restoration was approaching the structure of long-established ones.

B．Much of the wilderness of the fields was owed to birds.

C．Previous ground disturbance aided the woodland establishment.

D．How quickly the fields returned to wilderness over time.

4. What does the last paragraph mainly talk about?

A．The essential role of humans in the reforestation.

B．The factors that contribute to the reforestation.

C．The importance of woodland establishment.

D．The threats faced by a handful of wild animals.