hmm...., i think 'D' is the answer according to first paragraph
Hello!I'm preparing for the toefl and since i began my preparation my reading score decreased rapidly!!!!
Why can be this possible????
I read the whole passage carefully and go back to the passage every question!!!
Here are some of the errors i made and can't understand!
Here is the text:
The elements other than hydrogen and helium exist In such small quantities that it is accurate to say that the universe somewhat more than 25 percent helium by weight and somewhat less than 25 percent hydrogen.
Astronomers have measured the abundance of helium throughout our galaxy and in other galaxies as well. Helium has been found In old stars, in relatively young ones, in interstellar gas, and in the distant objects known as quasars. Helium nuclei have also been found to be constituents of cosmic rays that fall on the earth (cosmic "rays" are not really a form of radiation; they consist of rapidly moving particles of numerous different kinds). It doesn't seem to make very much difference where the helium is found. Its relative abundance never seems to vary much. In some places, there may be slightly more of it; In others, slightly less, but the ratio of helium to hydrogen nuclei always remains about the same.
Helium is created in stars. In fact, nuclear reactions that convert hydrogen to helium are responsible for most of the energy that stars produce. However, the amount of helium that could have been produced in this manner can be calculated, and it turns out to be no more than a few percent. The universe has not existed long enough for this figure to he significantly greater. Consequently, if the universe is somewhat more than 25 percent helium now, then it must have been about 25 percent helium at a time near the beginning.
However, when the universe was less than one minute old, no helium could have existed. Calculations indicate that before this time temperatures were too high and particles of matter were moving around much too rapidly. It was only after the one-minute point that helium could exist. By this time, the universe had cooled sufficiently that neutrons and protons could stick together. But the nuclear reactions that led to the formation of helium went on for only a relatively short time. By the time the universe was a few minutes old, helium production had effectively ceased.
13. According to the passage, helium is
(A) the second-most abundant element in the universe
(B) difficult to detect
(C) the oldest element in the universe
(D) the most prevalent element in quasars
What is your answer????
And please show me where in the passage is stated the answer!!!!
Thank you PINTUDAO!!!
By the way, nice avatar you have!!!
I can't stop watching it!!!
Originally Posted by EllinikI think there is some sort of typo or other error in the TOEFL reading here--hydrogen makes up approximately 75% of known matter, so I think your first paragraph should read:The elements other than hydrogen and helium exist in such small quantities that it is accurate to say that the universe is somewhat more than 25 percent helium by weight and somewhat less than 75 percent hydrogen.This would also make sense in context, since all other elements are negligible in terms of the percentage.
And I think you can get the answer now, right?
☼ Waiting for Godot
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