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	<question>
		<phrase isaudiomp3="1" mp3="AUDIO_REPOS/8.0.mp3"></phrase>
		<question isaudiomp3="1" rationale="0" picture="images/question8.jpg" mp3="AUDIO_REPOS/2060-8" 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/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/8.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Martian space rocks tend to be very old, but shergottites are generally thought to be remarkably young.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/9.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Most scientists believe they were formed as a result of volcanic activity about 150 to 250 million years ago.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/10.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[This would mean they formed during Earth's Jurassic period, when dinosaurs roamed the land.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/11.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[If so, shergottites are a sign that Mars might have been geologically active fairly recently.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/12.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[That in turn means it might still have been friendly to some form of life, said planetary geochemist Munir Humayun.]]></answer>
	</question>

	<question>
		<phrase isaudiomp3="1" mp3="AUDIO_REPOS/20.0.mp3"></phrase>
		<question isaudiomp3="1" rationale="0" picture="images/question20.jpg" mp3="AUDIO_REPOS/2060-20" 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/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/20.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[Researchers generally measure certain radioactive elements in rocks to figure out how long a rock has been around.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/21.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[But when the meteorites slam into Earth, that melts the rock down and can erase the evidence.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/22.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[That's why scientists picked the tiny baddeleyites: Once they form, they are durable little minerals.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/23.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[It's not easy to melt them down.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/24.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[By looking at the radioactive uranium and lead in this tough rock, the scientists found that it formed sometime around 187 million years ago.]]></answer>
		<answer isaudiomp3="1" picture="images/c1.jpg" mp3="AUDIO_REPOS/2060-1" isrationalemp3="1" rationalemp3="AUDIO_REPOS/right.mp3" rationaleimage="images/rationale/25.1.jpg" rationale="Right" value="1" choicesay=""><![CDATA[This proved that the baddeleyites were young.]]></answer>
	</question>

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