China has planted millions of trees in its north over the past two decades as part of its fight against expanding deserts.
   The effort paid off.Around the year 2000，deserts across the country were still expanding by 10，400 k㎡ a year.But in 2017，the State Forestry Administration reported that China's deserts were decreasing by more than 2，400 k㎡ a year.The achievement was confirmed by a 2018 study from the Laboratory of Climate and Environmental Sciences in Paris.
   "In 1999，the Chinese government began planting millions of trees in its Grain for Green Program.It was intended to repair damaged farmland in the northern Loess Plateau，which is roughly the size of France，" says Philippe Ciais，a climate researcher at the laboratory. "I was there a few months ago，and it is indeed amazing that once bare landscapes are now almost fully covered by plants."
   And China is doubling its effort and has announced a target of 30% forest coverage by 2050.At the moment，the coverage is 22%.
   "The growth of forests is significant and necessary progress in the fight against desertification，" says Jianping Huang，a climate researcher at Lanzhou University. "But it's still too early to determine whether it has solved the problem.In northwestern China，researchers have found that many of the plant species introduced to the Loess Plateau use more water than native vegetation.A 2016 study found that the restored ecosystem was already using too much rainfall and reducing the amount of water that runs off to rivers.It could lead to water shortages for humans."
   Considering water shortages is important，the national forestry department has recognized the error of planting trees in dry areas.In recent years，it has worked more closely with researchers and communities to find ways to seed less-thirsty plants that have economic value.These include plants used in traditional Chinese medicine，which farmers can harvest and sell. "All programs need to take into account local conditions，" the forestry department said in March. "Our efforts should go towards keeping vegetation healthy，rather than simply planting trees. "

（1）What is the second paragraph mainly about？
A．The effort of planting trees.
B．The worsening desertification.
C．The hard fight against expanding deserts.
D．The result of the Grain for Green Program.
（2）What is China's target for forest coverage by 2050？
A．22%.
B．30%.
C．44%.
D．52%.
（3）What is Jianping Huang concerned about？
A．The rapid growth of the foreign species.
B．The fast losses of native plants and trees.
C．The war for water between trees and humans.
D．The quickly declining rainfall in the dry areas.
（4）What has the forestry department learned from the tree-planting effort？
A．To put economic value first.
B．To consider the income of all parties.
C．To base its decisions on local conditions.
D．To wait for complete scientific evidence.

【考點(diǎn)】說(shuō)明文．

【答案】D；B；C；C