beyond the tree line,they eventually can sprout (发芽) new trees.This explains how a forest can move.Of course,the process would work only if the tundra were warm enough.But
in recent years,the whole planet has been warming.
New trees will provide shelters for some snow.Keeping
the sun’s rays from making the white surface disappear.Instead,the trees absorb the sun’s heat.This warms the surrounding air.The extra warmth encourages even more trees
to produce seeds.That further boosts a forest’s ability to expand.In
addition,more
trees
will
trap
more
snow,preventing much of it from being blown away.Snow can trap heat in the soil below,which encourages trees to grow.The recent rise of temperatures has helped more trees grow past the
tree line.People worry about impacts on the animals that
depend on frozen conditions for food and shelter.
1.What is the main cause of the trees in the Arctic moving northward?
A.The shrinking of northern tundra.
B.The rising temperature.
C.The fierce and cold wind.
D.The abundant resources in the north.
2.What does the underlined word “ this”
in Paragraph 2 mean?
【2016届高三英语二轮复习课时训练:17 阅读理解+完形填空+语法填空+短文改错】相关文章:
★ 2017届高考英语二轮复习大题冲关秘籍完形填空之记叙文:命题趋势(含解析)
★ 2017届高考英语二轮复习大题冲关秘籍完形填空之夹叙夹议文:体验真题(含解析)
★ 2017届高考英语二轮复习大题冲关秘籍完形填空之夹叙夹议文:创新押题(含解析)
★ 【三维设计】2017届高考英语(江苏专用)二轮复习阅读理解解题技法示范课件:10
★ 2017届高考英语二轮复习大题冲关秘籍语法填空:创新押题(含解析)
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ规范练:2(含解析)
★ 【优化方案】2017届高考英语二轮复习全国卷Ⅱ题型重组训练:第11组(含解析)
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21