The phrase "All in all "in the passage is closest in meaning to .............

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. 

Who is the most likely speaker?

The word “sensational” is closest in meaning to .............

It can be inferred from the passage that research concerning the distress signals of trees ...............

The word “plight” in paragraph 1 is closest in meaning to ..............

How many known kinds of plants and animals call the rain forests their home?

According to the passage, we can infer that .........

According to the passage, it is believed that the largest extinction of a species occurred ...........

The passage states that one solution to time management problem is to ..............

The word “pseudonym” in the passage refers to ___________.

Which of the following is NOT mentioned in the passage?