更多"More and more of the world’s supply"的相关试题:
[单项选择]More and more of the world’s supply of seafood is coming from farms.
Although 80% of the world’s seafood comes from marine harvests, there is a major shift under way toward aquaculture now.
Nearly 40% of salmon marketed today are raised in captivity, compared with 6% a decade ago. Forty percent of all clams, oysters, and mussels are produced in farm environments, along with 65% of freshwater fish. Between 1990 and 1996, fish-farming production rose from 12.4 million to 23 million tons worldwide, writes Anne Platt McGinn in an article for World Watch magazine.
"The fact that world seafood supplies continue to increase at all is due almost entirely to the phenomenal growth in aquaculture," says McGinn, a research associate at the World Watch Institute. Commercial aquaculture is driven by rising human population at a time when over harvested wild fish stocks are in decline and conventional farm production has leveled off.
Biotechnology is contributing to high-yield aqu
A. the human population is increasing fast.
B. the wild fish stocks are decreasing due to over fishing.
C. the cost of developing aquaculture is comparatively low.
D. there is no improvement in conventional farm production.
[单项选择]
More and more of the world’s supply of seafood is coming from farms.
Although 80% of the world’s seafood comes from marine harvests, there is a major shift under way toward aquaculture now.
Nearly 40% of salmon marketed today are raised in captivity, compared with 6% a decade ago. Forty percent of all clams, oysters, and mussels are produced in farm environments, along with 65% of freshwater fish. Between 1990 and 1996, fish-farming production rose from 12.4 million to 23 million tons worldwide, writes Anne Platt McGinn in an article for World Watch magazine.
"The fact that world seafood supplies continue to increase at all is due almost entirely to the phenomenal growth in aquaculture," says McGinn, a research associate at the World Watch Institute. Commercial aquaculture is driven by rising human population at a time when over harvested wild fish stocks are in decline and conventional farm production has leveled off.
Biotech
A. the human population is increasing fast.
B. the wild fish stocks are decreasing due to over fishing.
C. the cost of developing aquaculture is comparatively low.
D. there is no improvement in conventional farm production.
[单项选择]The world’s oil supply （ ）.
A. have been gradually being exhausted
B. is being gradually exhausted
C. is gradually exhausted
D. has gradually exhausted
[填空题]More and more of the world’s population are living in towns or cities. The speed at which cities are growing in the less developed countries is (26) . Between 1920 and 1960 big cities in developed countries (27) two and a half times in size, but in other parts of the world the growth was eight times their size.
The (28) size of growth is had enough, but there are now also very (29) signs of trouble in the (30) of percentages of people living in towns and percentages of people working in industry. During the nineteenth century cities grew as a result of the growth of industry. In Europe the (31) of people living in cities was always smaller than that of the (32) working in factories. Now, however, the (33) is almost always true in the newly industrialized world: (34) .
Without a base of people working in industry, these cities cannot pay for their growth; (35) . There
