13．
Red squirrels used to be a common sight in British forests and countryside．But there are fewer than 140，000red squirrels left now and most of them are in Scotland．However，grey squirrels （introduced from North America） are now so common that many people dislike them．They can be legally（合法的）trapped and destroyed．
On first sight，the two types of squirrel are similar．They both have a long tail，which helps the squirrel to balance when jumping from tree to tree，and the same large eyes，small ears and powerful back legs．However，the grey squirrel has a clear physical advantage over the red．The red squirrel has a head-and-body length of 19to 23centimeters，a tail length of 15to 20centimeters and a body weight of 250to 340grams．Compared to this，the grey squirrel is a larger animal．The head and body measures between 23and 30centimeters long and the tail is between 19and 25centimeters long．Adult grey squirrels are heavier，weighing between 400and 600grams．This size allows them to store more fat and helps them to survive a hard winter，which would be fatal（致命的）to their smaller cousins．
So why are red squirrels losing out in competition with grey squirrels？Size is one factor，but there are others．Red squirrels live high up in trees，while grey squirrels spend more of their time on the ground．This means any loss of forests greatly influences the red squirrel population．Another reason for the grey squirrel's success is its ability to use food provided by people．Like the fox，the grey squirrel can survive in towns and cities．The other problem for the red squirrel is disease．Both squirrels carry a certain virus．While this doesn't seem to attack grey squirrels，it is fatal to red squirrels．
69．Which are introduced from North America，red squirrels or grey squirrels？Grey squirrels．
70．What helps the squirrel to balance when jumping from tree to tree？Their long tail．
71．How much do adult grey squirrels weigh at most？They weigh 600 grams
72．Who are the"smaller cousins"mentioned in the second paragraph？The Red squirrels．
73．There are four reasons why red squirrels are losing out in competition with grey squirrels．Please list TWO of them．（每條不得超過(guò)4個(gè)單詞）（1）Grey squirrels are bigger．（2）Loss of forests..（3）Eating habits．（4）The Virus．
新題型全程檢測(cè)期末沖刺100分系列答案
