A shocking news report has revealed that more than one in five species of maple （楓樹）trees faces extinction，warning that 75% of the threatened species are "geographically restricted" in their native regions.
The trees are experiencing a vast decline in habitat，due to urban development，wood harvesting and agricultural expansion.Time is running out for the world's biodiversity.Every recent survey of plants and animals in the wild points to this.This is happening nearly everywhere rarer maples exist.And because of climate change，the narrow habitats that support species at the edges of dry places and at the tops of mountains are quickly disappearing.
The trees can be found in subtropical and tropical regions，as far south as Indonesia.The only species found in the UK，the field maple is not under threat.Not only are the trees a popular attractive feature in parks and public spaces，but they are a key part of the natural ecosystem in woodlands，as well as being an important wood crop in several countries.Although the sugar maple in North America，which produces maple juice，is not endangered，two of the closest relatives to the species are endangered.
The report notes that conserving at-risk species in their natural habitat is the best conservation
tactic.But collections in botanical gardens and seed banks- called "ex situ collections" can act as insurance policies against extinction.There are currently 14 species of maple，including four that are critically endangered，which are absent from these types of collections.
One species in Mexico，the Acer binzayedii，is in "desperate need of conservation" despite only being discovered in 2017. "It is at risk from climate change in its cloud forest habitat and threatened by logging and forest fires while it is also absent from 'ex situ collections'，" the report adds.The report recommends developing conservation plans，monitoring species currently not at risk to ensure populations are maintained，and adding those missing maple species to seed banks.
（1）What is paragraph 2 mainly about？
B
B
A．Action to protect maple trees.
B．The dangerous situation of maple trees.
C．Various maple trees' habitats in the world.
D．The conditions for diversity in maple trees.
（2）What do the field maple and the sugar maple have in common？
C
C
A．They cannot produce juice.
B．They are found in America.
C．They are not at risk of extinction.
D．They have two endangered relatives.
（3）What does the underlined word "tactic" in paragraph 4 probably mean？
B
B
A．Topic.
B．Approach.
C．Result.
D．Conclusion.
（4）What's the main purpose of the report？
A
A
A．To offer a proposal.
B．To recommend a product.
C．To introduce maple species.
D．To warn people of disasters.
