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<catalog>
	<question>
		<phrase isaudiomp3="1" mp3="AUDIO_REPOS/1.0.mp3"></phrase>
		<question isaudiomp3="1" rationale="0" picture="images/question1.jpg" mp3="AUDIO_REPOS/2062-1" exercise_type="" questionmode="" choicemode="" answerbankid="" answerbankmode="" rationalemode="" playonload="" mp3speed="" ttsspeed="" passage="1" show_passage="" show_passage_audioplayer="" passage_audio_type="" showvideo="" video="" enable_audio_recorder="" recorder_mode=""><![CDATA[]]></question>
		<saythis><![CDATA[]]></saythis>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/1.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[LOS ANGELES  -  Planetary scientists dream of sending a geologist to Mars to study its rocks by hand.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/2.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Until then, they have to settle for examining meteorites  -  chunks of the Red Planet that land on Earth after hurtling through space and surviving the searing fall through our atmosphere.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/3.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Though a little banged up, these meteorites provide a vital up-close view of our rust-hued neighbor.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/4.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[But it can be hard for geologists to interpret what they see when they can't agree how old a rock is.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/5.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Conflicting age estimates for certain rocks differ by up to 4 billion years  -  the vast majority of Mars' planetary existence.]]></answer>
	</question>

	<question>
		<phrase isaudiomp3="1" mp3="AUDIO_REPOS/6.0.mp3"></phrase>
		<question isaudiomp3="1" rationale="0" picture="images/question6.jpg" mp3="AUDIO_REPOS/2062-6" exercise_type="" questionmode="" choicemode="" answerbankid="" answerbankmode="" rationalemode="" playonload="" mp3speed="" ttsspeed="" passage="1" show_passage="" show_passage_audioplayer="" passage_audio_type="" showvideo="" video="" enable_audio_recorder="" recorder_mode=""><![CDATA[]]></question>
		<saythis><![CDATA[]]></saythis>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/6.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[In a paper last month in the journal Nature, an international team of scientists sought to sort out this issue for a particular group of meteorites known as shergottites.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/7.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Martian space rocks tend to be very old, but shergottites are generally thought to be remarkably young  -  forming as a result of volcanic activity about 150 million to 250 million years ago, around the same time that dinosaurs roamed during Earth's Jurassic period.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/8.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[If so, shergottites are a sign that Mars might have been geologically active fairly recently, and thus perhaps still amenable to some form of life, said Munir Humayun, a planetary geochemist at Florida State University who was not involved in the study.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/9.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[But a few researchers recently estimated that shergottites are about 4 billion years old  -  a finding that had far-reaching implications for scientists' understanding of Mars' history."]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/10.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Most of us understand that if there is to be life on Mars it's not going to be roaming on the surface, but it could be thriving underground with the heat energy provided by volcanism," Humayun said.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2062-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/11.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[But "if there hasn't been (volcanic activity in) 4 billion years ... it would be very difficult to believe there was life left on Mars."]]></answer>
	</question>
	
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