SECTION D NOTE-TAKING AND GAP-FILLING

　　In this section you will hear a mini-lecture. You will hear the lecture ONLY ONCE. While listening to the lecture, take notes on the important points. Your notes will not be marked, but you will need them to complete a 15-minute gap-filling task on ANSWER SHEET ONE after the mini lecture. Use the blank sheet for note-taking.

　　Making Artificial Diamond

　　Diamond are a form of (16), which is a very common element. Scientists began to make artificial diamonds from the (17) century. The first real success came in the laboratory of a (18). To make synthetic diamonds, what was needed was a pressure (19),and a (20) of between 2200 and 4400 F. Even with this equipment, scientists    produced all sorts of (21), but no diamonds. The idea was then brought forward that perhaps the carbon needed to be dissolved in a    (22), which helps a chemical reaction to take place more easily. Later, the carbon was mixed with (23). The pressure was bought up to 1,300,000 pounds to the square inch, and the temperature    to (24).

　　At last, a number of shiny crystals were produced, which were analyzed    both chemically and under (25), and there was no longer room for doubt. They were not like diamonds. They were diamonds.

　　PART II PROOFREADING & ERROR CORRECTION

　　The following passage contains ten errors. Each line contains a maximum of one error. In each case only one word is involved. You should proofread the passage and correct it in the following way:

　　For a wrong word, underline the wrong word and write the correct one in the blank provided at the end of the line.

　　For a missing word, mark the position of the missing word with a "^" sign    and write the word you believe to be missing in the blank provided at the end    of the line.

　　For an unnecessary word, cross the unnecessary word with a slash "/" and put the word in the blank provided at the end of the line.

　　EXAMPLE

　　When ^ art museum wants a new exhibit,

　　(1) an

　　it (never/) buys things in finished form and hangs

　　(2) never

　　them on the wall. When a natural history museum

　　wants an exhibition, it must often build it.

　　(3) exhibit

　　Vitamins, like minerals, are chemicals. There is

　　absolutely not difference in the chemical structure

　　(26)

　　of the nature vitamin C and the chemical structure

　　(27)

　　of the synthetic vitamin C. Also, while most sub-

　　stances are harmless at very low level of intake, all

　　(28)

　　substance —— even the elements that are essential to

　　life —— can be dangerous if you overdo them. Take water

　　for example. Six or eight glasses a day will keep your

　　body in good fluid balance. But you can also be drown

　　(29)

　　in it. Some people argue that individuals vary greatly

　　(30)

　　in their need for nutrients, it cannot necessarily be

　　stated any given amount is too much; that is all

　　(31)

　　relative. But since there is little solid information

　　on what is the optimal intake of any essential nutrient

　　in healthy individuals, it would be impossible to give

　　guidelines that take these proportional needs into the

　　(32)

　　account. Just as with other drugs, the relation to

　　(33)

　　different vitamin dosages varies, with some people

　　better able than others to tolerate large amounts. While

　　we do know that very specifically what the toxic level

　　(34)

　　is for vitamins A and D, we are far less sure about

　　vitamin E, even though it, too, is fat-soluble, and we

　　still dont understand the water-soluble vitamin, the C

　　(35)

　　and the B groups, which the body cant store.