【推荐1】Directions: After reading the passage below, fill in the blanks to make the passage coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word; for the other blanks, use one word that best fits each blank.

Can Indoor Plants Really Purify the Air?

Plants are very important to human life. Through photosynthesis(光合作用), they transform carbon dioxide into fresh oxygen. They     1     (assume) to remove toxins from the air we breathe -- but is this true?

One famous NASA experiment published in 1989 has found indoor plants can clean the air by removing pollutants     2     cause cancer. Later research has found soil micro - organisms in the potted plant also     3     (play) a part in cleaning indoor air.

Based on this research, some scientists say house plants are effective natural air purifiers, and the bigger and leafier the plant, the better. The amount of leaf surface area influences the rate of air purification.     4     , however, say the evidence that plants can effectively accomplish this feat(功绩)is far from conclusive.

“There are no definitive studies to show that     5     (have) indoor plants can significantly increase the air quality in your home,” According to Luz Claudio, a professor of environmental medicine and public health. “There’s no question     6     plants are capable of removing volatile(易挥发的)chemical toxins from the air under laboratory conditions,” says Claudio. But in your home or office space, the notion that putting a few plants together can purify your air doesn’t have much hard science     7     (back) it up.

Most research efforts to date, including the NASA study, placed indoor plants in small,     8     (seal) environments to assess how much air-purifying power they have. “But those studies aren’t really applicable to what happens in house. In many cases, the air in your home completely turns over -- that is, exchanges places with outdoor air -- once every hour. In most instances, air exchange with the outside has a     9     (great) effect on indoor air quality than plants.” says Stanley Kays, a professor of horticulture(园艺学).

Disappointed     10     many people may be by what Kays said, the professor also made it clear that he believes house plants are beneficial. Studies have shown plants can knock out stress and make people feel happier. More research shows spending time around nature has a positive effect on a person’s mood and energy levels.

【推荐2】阅读下面短文，在全白处填入1个适当的单词或括号内单词的正确形式，并将答案填写在答题卡上。

Ateam of biologists studied rain frogs in the forests of northern Ecuador. While doing so, they made a surprising    1    (discover): a Mindo harlequin toad(丑角蟾).It was 30 years since the creature    2    (see) alive. The scientists couldn't believe their eyes.

The Mindo harlequin is the latest harlequin toad species to come back from the dead. Since 2003, eight others have ken found, three of them in Ecuador. Until    3    (recent), 13 of the 25 species of harlequin toads in Ecuador have gone unseen since the 1980s or early 1990s. Scientists thought most of them had been wiped out by a disease    4    (call) chytrid, which is especially    5    ( harm) to the harlequin toad. The Mindo harlequin may have developed a resistance (抵抗力)to the disease,    6    would explain their reappearance. And it could spell good news forother harlequins. Since discovering the first one, the team have found five    7    (many). They were all tested for the disease but none of them had. But that doesn’t mean the survival of the species is guaranteed. The harlequin toad is still endangered.

Biologists are developing a conservation plan together    8    a zoology museum in Ecuador. They want to make sure the Mindo harlequin toad doesn't fall back into extinction. Each reappearance gives us    9    second chance to develop better conservation ways. Not every day do we have the opportunity    10    (save) a species that we believed to be extinct.