All the following are mentioned as events that can affect food supply EXCEPT .
A.erosion of soil
B.contamination of soil
C.reduction of nutrients
D.loss of water supply

VII. From the four words or phrases choose the one that best completes the sentence.
Green plants combine ______ with water and carbon dioxide to make food.
A.energy derived it from light
B.energy derived from light
C.energy is derived from light
D.from light, and energy derived

VII. From the four words or phrases choose the one that best completes the sentence.
Only by reproducing at a tremendous rate ______ to survive in the sea.
A.many plant and animal species manage
B.do many plant and animal species manage
C.manage many plant and animal species
D.plant and animal species manage many

He doesn't have any informations about the departure and arrival time of today's flights.
A.informations
B.about
C.time
D.today's

The mother asked her son what did he want for his birthday.
A.asked
B.her son
C.did he want
D.his

Throughout the United States there is fast food restaurants where hamburgers a are served.
A.Throughout
B.is
C.where
D.are served

Helen was proud for finishing the work in such a short time.
A.for
B.finishing
C.such
D.a short time

IV. Choose the word or phrase - A, B, C or D - that needs correcting.
They are planning (A) on attending (B) the convention next month, and (C) so I am (D).
A.planning
B.on attending
C.and
D.so I am

IV. Choose the word or phrase - A, B, C or D - that needs correcting.
Because of its (A) vast tracts of virtually (B) uninhabited northern forest, Canada has one of the lowest (C) population density (D) in the world.
A.its
B.virtually
C.lowest
D.density

V. Fill in each blank space with one appropriate from the box. .
The Great Wall is probably China's best-known monument and one of its (26) popular tourist destinations. In 1987 it was designated a World Heritage Site by the United Nations Educational, Scientific and Cultural Organization (UNESCO). The Great Wall is not a (27) , continuous structure. Rather, it consists of a network of walls and towers that leaves the frontier open in places. Estimates of the total length of the monument vary, depending on (28) sections are included and how they are measured. The Great Wall is about 2,400 km (about 1,500 miles) long, (29) conservative estimates. Other estimates cite a length of 6,400 km (4,000 miles), or even longer. Some long-standing myths about the wall have been dispelled in recent decades. The existing wall is not several thousand years old, nor is it, as has been widely asserted, visible with the (30)______ eye from outer space. (Astronauts have confirmed this. However, same of the wall is discernible in special radar images taken by satellites.)
(27)
A.single
B.alone
C.lonely
D.separated