Researchers Look to Sodium to Make Better Batteries

level = 8

1:05

about one hour ago

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toefl ibt audio 3

level = 14

4:06

5 hours ago

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The history of the world according to cats - Eva-Maria Geigl

level = 16

4:56

4 days ago

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toefl ibt audio 2

level = 13

5:23

5 days ago

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toefl ibt audio 1

level = 16

2:45

5 days ago

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DNA Technology Helps Famers Identify Crop Diseases

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3:17

7 days ago

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The Gruffalo first part

level = 9

2:25

14 days ago

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a kiss

level = 11

1:30

15 days ago

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China Lands Spacecraft on 'Dark' Side of Moon

level = 9

1:30

18 days ago

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Man in the mirror

level = 2

0:16

18 days ago

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