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《Using LanguageⅠ》最新PPT课件优质课下载
ZhouHeping wants to find out how archaeologists make sure that early people's dates according to their bones.
1. Listen to Part 1 of the tape and fill the layers in the “wastepaper basket” diagram below.
yogurt pots
orange skin
wastepaper
used envelopes
The waste paper basket
Listen to Part 2 and complete the passage.
It uses radioactivity to measure the amount of _______ in living things. The ________ in a dead body _________ at a ____ rate. We know how long that takes, so we can measure the amount of ______ and ________ how old a bone is.
carbon
carbon
disappears
fixed
carbon
work out
Look at this archaeological drawing of a
section showing buildings at different times
and work out the order in which they were
built.
Answer key for Exercise 3:
The oldest building is B because it has no layers underneath it.
The second oldest building is C because it has one layer underneath it. That layer is the remains of the building in B.
The most recent building is building A. It has two layers underneath. They are the remains of buildings B and C.
THE FEAST: 18, 000 BC
Can you guess what would be eaten on