完形填空.As temperatures rise and the polar ice caps melt,the ra

完形填空.
As temperatures rise and the polar ice caps melt,the race is 11 to unlock the treasures of the Arctic.
This region is thought to contain one quarter of the world's untapped oil and gas 12,and there's stiff competition 13 them.America,Canada,Denmark and Norway have all staked territorial claims in the Arctic,and 14 has Russia.
Three years ago,a Russian 15 planted a titanium flag 16 the ocean floor 17 the North Pole.It was a symbol of Moscow's 18 to protect what it sees as its national interest.
In Moscow this week scientists,businessmen and politicians 19 Arctic nations will discuss co-operation,but they're also expected to push their countries' 20 in the region.
11.A.in B.at C.on D.off
12.A.sources B.reserves C.stores D.savings
13.A.in B.at C.as D.for
14.A.as B.like C.so D.such
15.A.trip B.journey C.expedition D.mission
16.A.in B.at C.for D.on
17.A.beneath B.down C.low D.into
18.A.determination B.faith C.courage D.bravery
19.A.away B.off C.from D.towards
20.A.speech B.claims C.assertion D.accounts