Complete the following passage by using the words in the box. Each word can only be used once. Note that there is one word more than you need.
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A. recently B. affects C. pattern D. varied E. floats F. warm G. regularly H. mysterious I. effect J. evidence |
Big climate changes in the last million years might have come from something very small: dust from outer space.
Earth changes between ice ages and warm periods in a(n) __1.__ that includes several cycles, including a __2._ one that lasts 100,000 years. Scientists __3.__suggested this cycle might be due to changes in the inflow of cosmic(����) dust.
The idea is that Earth _4.__above and below the imaginary plane that runs through the sun and Jupiter(ľ��), completing a cycle every 100,000 years. So maybe it encounters __5._varying amounts of dust during each cycle that produce the climate trend.
Now there is some __6.__, from ancient cosmic dust recovered in ocean-floor drilling near the Azores islands west of Portugal. The large quantity of the dust rises and falls with a wonderful 100,000 year cycle during the period analyzed, 253,000 years to 458,000 years ago. Periods of more dust are related to__7.__ climates.
But that is a long way from showing that the dust __8.__ climate. Some scientists argue that it is not clear how cosmic dust would make the climate warmer while dust from volcanoes is known to make it cooler. They say the cosmic dust is so thin that it is hard to see how it could have any climate__9.__.
Nevertheless, the new study shows scientists have to take the cosmic dust idea seriously.
Mr. Bush is on time for everything. How_____ it be that he was late for the opening ceremony?
A. can B. should C. may D. must
Some people hold that, since we live in a money-oriented society, the average individual cares little about solving ______ problems.
A. anyone elses’ B. anyone’s else C. anyone else’s D. any one else’s
Contemporary English is quite different from Old English. There has never been a year ______ the language was not changing.
A. that B. when C. for D. until
This is the most important assignment facing American journalism — to make _____ clear to the reader the problems of the day.
A. it B. that C. / D. this
He was so absorbed in his work that not a sound ______.
A. did she dare to make B. dared she to make
C. she didn’t dare to make D. she dared to make
