Today I’d like to begin a discussion on the problem of the heating up the earth. First, we’ll touch on the relationship between fluorocarbons and the ozone layer. You probably remember that the ozone layer is the protective shield around the earth. It is important to all life, because it filters out harmful ultraviolet light from the sun. Ozone itself, a form of oxygen, is regularly made by the action of the sun in the upper atmosphere. It is also regularly destroyed by natural chemical processes.

The problem now is that too much of the ozone layer is being destroyed. Scientists suspect that certain chemicals, such as fluorocarbons, are contributing to the depletion of the ozone layer. And how do we use fluorocarbons? The most common uses are in spray cans and cooling systems. The chemical pollution from these fluorocarbons can account for some of the ozone losses that have been reported. There are, however, new studies linking the sun itself to the depletion of the ozone layer. We’ll go into that new study more next time.

What will the speaker probably discuss next?

Which of the following is closest in meaning to the word “tuck”?

How did the publication of Moby Dick affect Melville’s popularity?

The phrase “do this” in the first paragraph mostly means ______.

What does the phrase “you have got it out of your system” in passage mean?

The author implies that the mammals of the "suburban forest" differ from most species of trees there in which of the following ways?

Which of the following statement is supported by the passage?

According to paragraph 4, which of the following is the most fascinating to booklovers?

Which sentence about Joseph Pulitzer is NOT true according to the reading passage?

What does the passage mainly discuss?

How was the public motivated to help the health workers?

The word “it” in the second paragraph refers to ________.

The passage implies that Melville stayed in Tahiti because ...........

The word “Ornaments” in paragraph 3 is closet in meaning to _______.

What does the word magni stand for?

The passage mainly discusses Rachel Carson’s work ............

According to the article the Feingold diet is NOT ___________.

The phrase “For example,” line 19, introduces a sentence that gives examples of ........

In order to show that learning to write requires effort, the author gives the example of ................

Normal human beings .................

Who were the first people to have seen these apelike creatures before the five campers?