Question

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.

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) ____ that includes several cycles, including a ___ one that lasts 100,000 years. Scientists ____suggested this cycle might be due to changes in the inflow of cosmic(宇宙) dust.

   The idea is that Earth ___above and below the imaginary plane that runs through the sun and Jupiter(木星), completing a cycle every 100,000 years. So maybe it encounters ___varying amounts of dust during each cycle that produce the climate trend.

   Now there is some ____, 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____ climates.

   But that is a long way from showing that the dust ____ 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____.

   Nevertheless, the new study shows scientists have to take the cosmic dust idea seriously.

Answer 1

【小题1】C

【小题1】H

【小题1】A

【小题1】E

【小题1】G

【小题1】J

【小题1】F

【小题1】B

【小题1】I

解析:

略