阅读理解。

     A vertical farm is a concept farm which is planted on levels or floors.A sky scraper type

building can house a vertical farm.Since the garden is built upwards,rather than outwards,it

requires much less space than a conventional(传统的) farm.

     The world is quickly running out of room for conventional farming.Vertical farms could be

a key to this situation.An 18story vertical farm could feed as many as 50,000 people,all in an

area which is the size of the average city block.Vertical farms in the city could cut down on

transportation costs as well.Think about the amount of fuel it takes to transport food from

farmland to city.The resources saved would be surprising. Besides saving travel time,food

would be delivered in fresher condition and with less damage.

     There is a growing concern about the use of pesticides in agriculture today.But the vertical

farm would be a greenhouse type environment, avoiding the need for a large number of

pesticides.Vertical farms can be built in a contained space,therefore they are an excellent

solution for living well in an environment far different from our own.Hydroponics(水耕法)

could be a big part of vertical gardening.This would reduce the amount of soil needed to grow

food.Of course,not all food does well with this type of planting,but there are many crops

that actually seem to do better.

     In some climates,a lack of sunlight creates a short growing season. The solar power option

may not work as well here.The addition of grow lights would make it possible to grow crops

in vertical gardens in these areas.In other words,we could grow crops in areas where we never

could before.

     Vertical farms may just be a concept for now,but they are a concept that will solve many

of our problems in the future.

1.According to the passage, a vertical farm________.

A．is mainly built outwards

B．is only an environmental friendly farm

C．is planted on levels upwards

D．is dependent on solar power

2.The second paragraph is mainly about________.

A．the meaning of a vertical farm

B．the future of a vertical farm

C．the cost of a vertical farm

D．the benefit of a vertical farm

3.Compared to the conventional farm, the vertical farm can________.

A．help to protect the limited gardens  

B．reduce the harmful effect of pesticides

C．depend far less on sunlight

D．greatly increase the use of soil

4.It can be learned from the passage that vertical farms________.

A．have been put into use

B．need less room than conventional farms

C．only use hydroponics to grow food

D．may increase the transportation costs

5.What would be the best title for the passage?

A．Vertical farms for our future

B．Vertical farms and green skyscrapers

C．Ways to deal with future problems

D．Advantages of vertical farms