In 1620, about half the USA was covered by forests． Today the forests have almost gone． A lot of good land has gone with them, leaving only sand． China doesn’t want to copy the USA’s example． We’re planting more and more trees． We’ve built the " Great Green Wall" of trees across northern part of our country．The Great Green Wall is 7,000 kilometres long, and between 400 and 1,700 kilometres wide． It will stop the wind from blowing the earth away． It will stop the sand from moving towards the rich farmland in the south． More "Great Green Walls" are needed． Trees must be grown all over the world． Great Green Walls will make the world better．

小题1:In 1620, about ______ the USA was covered by forests．

A．a third

B．half

C．two thirds

D．a fourth小题2:A lot of good land has gone with ______．

A．sand

B．water

C．wind

D．forests小题3:The Great Green Wall in China is ______ long．

A．7,000 kilometers

B．1,700 kilometers

C．7,000 meters

D．400 kilometers小题4:Trees must be grown in ______.

A．China

B．the USA

C．some countries

D．every part of the world小题5:_____ will make the world better．

A．The Great Wall

B．Tall buildings

C．Great Green Walls

D．Flowers and grass

下列哪些肾脏病变做CT平扫，呈"软组织密度"表现（）

A.肾结核

B.黄色肉芽肿性肾盂肾炎

C.肾脓肿

D.放线菌病

E.获得性囊性肾病变