Which of the following characterizes the history of impacts on Earth as deduced by impact history on other terrestrial planets?
A) Impact rates were very high in the early history of the earth, but dropped off after about the first 1 billion years of Earth history to a nearly constant rate since that time.
B) Impacts were more intense in the early history of the earth but have continued at about half the rate of bombardment since about 4.4 billion years ago.
C) Impacts continued at a fairly constant rate throughout the 4.5 billion year history of the solar system.
D) All major impacts occurred in the first 100 million years after the solar system formed.
A
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The Kyoto Protocol calls for an overall reduction of greenhouse gases of 5.3% below the 1990 levels. What was the average level of CO2 in 1990? What would the level of CO2 be if the Kyoto goal was met? How many ppm below current levels would that be? The “Group of 77” countries favor a 15% reduction below 1990 levels. What would that level be, and how far below present levels is it?
What will be an ideal response?
Judge the following sentence according to the criteria given below: The frequency of rockfalls can be
expected to increase with climate change BECAUSE retreating alpine glaciers can be expected to expose additional steep bedrock-walls. a. The assertion and the reason are both correct, and the reason is valid. b. The assertion and the reason are both correct, but the reason is invalid. c. The assertion is correct, but the reason is incorrect. d. The assertion is incorrect, but the reason is correct. e. Both the assertion and the reason are incorrect.
A(n) ________ is a structure in which the oldest rocks are located in the center
A) anticline B) syncline C) dome D) basin
________ is an atmospheric substance that is one of the substances causing the greenhouse effect
What will be an ideal response?