12．Christmas has never looked as beautiful as it is now，when this one-foot-tall mini tree grew from a pothole（坑洼）in the streets of London．
London pothole gardener Steve Wheen，34，has created over 150little gardens so far the smallest one of which is just one-inch-square．
"I really enjoy the reactions of people who come across my work and love them．"said Steve．"London can be so grey，especially at this time of year．When l was thinking about how to brighten it up，gardening came to my mind．"
Steve has been pothole gardening for four years，mainly around the streets of London His pothole gardens are made with some plants he chooses from his local garden centre．Each of them usually costs between five and ten pounds．Although they are often temporary to the streets，Steve is sure that they can be in people's mind for a long time，if they are lucky enough to come across these small gardens while they go about their daily lives．
"I'm always surprised when I ask people what they think the message is behind my Work．"he said．"Often they think I'm against or in honor of something．One person even considered that l was marking the places where people had died in car accidents．"
"I think in a city like London，where it's easy to feel short of green space，my message can be seen as a green one and that's fine with me．"he said．"The environment is something we all need to be thinking about more and more．But most importantly，it's all about making people smile and giving them an unexpected moment of happiness．"
21．Which of the following pictures can describe"a pothole garden"best？B
22．Steve thinks the main color of London around Christmas isC
A．white B．blue C．grey D．green
23．What does the underlined word"temporary"probably mean？A
A．lasting for a short time．B．beautiful but dangerous
C．strange to passers-by D．very expensive
24．Steve Wheen makes pothole gardens in London mainly toD．
A．be against or in honor of something
B．mark the places where car accidents happen
C．protect the environment
D．make people enjoy more greens．
