共用题干第一篇What are the advantages and disadv

共用题干

第一篇

What are the advantages and disadvantages of greenhouse technology?

There are many benefits of using greenhouses.Firstly,by using it,the productivity of the crop is increased considerably.Secondly,a superior quality can be obtained as they are grown under a better controlled environment. Thirdly,the percentage of germination of seeds is high in greenhouses.Finally,greenhouses allow an effective control of pests and diseases as the growing area is enclosed.
However,it has many disadvantages.On the one hand,greenhouses require a lot of work and constant maintenance.On the other hand,it is expensive to construct since gardeners will spend more money to buy a prefabricated greenhouse or to build a greenhouse than to plant directly in the ground or containers.Also,if Gardeners want to build their own greenhouses,they must pay highly for construction materials and sometimes,for additional labour. Moreover,greenhouses needs more space and homeowners need a very large space in their backyards or gardens for the greenhouse.Finally,the maintenance of the equipments used in greenhouses necessitates a lot of money and control.

What does the word"enclose"mean here? A:be close to B:put in an envelope C:surround completely D:introduce