英语阅读题~Around the world two thirds of the people are farmers.

英语阅读题~
Around the world two thirds of the people are farmers.most of them engage in subsistence farming.This means that they raise plants and animals to furnish their families with food and other supplies.They consume their varied output and have little to sell or to trade for other goods.Subsistence farms were common in the united states at one time,but there are few such farms today.
Two thirds of american farmers practice commercial farming.Commercial farms produce about 97 per cent of the country’s agricultural goods.These farms are operated much like other industries.The members of the farm family produce the commodities(商品) that will be sent to the market.They sell their products and buy the things they need.
Some commercial farms are big factories in the field.They may be owned by a company or by an individual as an investment.Most american farms,however,are still operated by families.A farmer may own or rent his land.
In a country as large as the united states,farms vary widely in climate,land surface,soil,water supply,convenience to market,and other characteristics.Different regions may have different kinds of specialized farms.Specialized farmers concentrate on the kind of farming best suited to the land and climate,to their technical skills,and to the money they invest in the farm.
However,no region is limited to a single type of farm.Indeed few farms are limited to one crop or commodity.Where output is varied and no one kind of crop or commodity produces more than half of a farm’s income,it is classified as a general farm.the general farmer grows varied crops to use the different kinds of soils or surfaces on his land and to employ his time and machinery most efficiently.
26．Subsistence farmers______
[a]grow crops for their families' own use
[b]sell a lot of their products for money
[c]trade their varied output for other goods
[d]use their agricultural products as commodities
27．Subsistence farms______.
[a]are very popular in the united states now
[b]are still common in many parts of the world
[c]consist of two thirds of the total number of the farms in the world today
[d]used to be the major form of farming in the world
28．American commercial farms______.
[a]furnish the country with two thirds of the food its people need
[b]are run in much the same way as other industries
[c]are all owned by different companies
[d]never rent their land for farming
29．A specialized farm is characterized by ______.
[a]its especially large size
[b]its independence of the market
[c]its concentration on a single type of farming
[d]its special way of operation
30．A farm is classified as general if ______.
[a]more than half of its income comes from varied crops
[b]it is limited to a single type of farm
[c]it employs different kinds of machines
[d] the soils or surfaces of its land are used most efficiently

a d b d d 差不多吧