a look at them before y"sThe Great

a look at them before y"s
The Great Wall has a histor
of more than
2.000
risk
of it ha
has been either lost or
ears.
But 51. 2 percen
Besides the influence
f w
ind and rai
f disappears
er0s1017
(侵蚀)，th
ne main reasons are human factors such
las tourism and human contact
loating Cin(移之成)
may not float for!
much longer as experts have warned that Venice could
go down under the water in a century
Since 1897, sea level in Venice has risen
by 30
centimeters， and the Mediterranean(地中海) will rise by
up to 1.4 meters before 2100.
At 423 meters below sea level, the Dead Sea is 10
times saltier than the ocean, meaning that even tourists
/who can't swim will be able to float. But it has lost al
Third of its surface area in the past 40 years because of thel
mineral(5)industry and farming