1. Since the early 1950’s, ________________ throughout the world has more than doubled.
A) the demand for food
B) there is demand for food
C) if food is in demand
D) food, a demand that
E) when the food demand
2. The different colors of ________________ the different temperature of the star’s surfaces.
A) the indication of stars
B) indicating stars
C) the indication that the stars
D) stars indicating that
E) the stars indicate
3. Only a few sounds produced by insects are heard by humans _____________ most of the sounds are pitched either too low or too high.
A) in spite of
B) since
C) as a result of
D) instead of
E) yet
4. Mathematics helps meteorologists to predict the weather more accurately, to calculate the speed of storms, and ____________.
A) for the wind to blow
B) causes the wind blowing to determine
C) to determine what causes the wind to blow
D) determine the wind’s blowing
E) to cause the wind
5. Systems of phonetic writing are ______________ at transcribing correctly and sequence of speech sounds.
A) the aim
B) aimed
C) who aims
D) by aiming
E) the aims
6. In photosynthesis, ____________ through which green plants manufacture food, energy form direct sunlight is trapped by a substance called chlorophyll.
A) that the process
B) is a process
C) in which the process
D) the process
E) the process of
7. _______________ and hard, ivory may be carved with great delicacy into intricate patterns.
A) The fact of dense
B) Its density
C) May be dense
D) Because of its density
E) Because it is dense
8. The spectacularly beautiful and sultry voice of Lena Home made her _________________.
A) a nationally celebrated vocalist
B) being a nationally celebrated vocalist
C) a vocalist was nationally celebrated
D) as nationally celebrated vocalist
E) a vocalist who nationally celebrate.
9. The existence of very long channels _______________ into the deep-sea floor of the Atlantic and Pacific oceans has been well documented.
A) are cut
B) cuts
C) to cut
D) cutting
E) cut
10. Dehydration is ________________ that a land animal faces.
A) the often gratest hazard
B) the greatest often hazard
C) often the greates hazard
D) often the hazard greatest
E) often the hazardous
11. The early railroads were _________________ the existing arteries of transportation: roads, turnpikes, and canals and other waterways.
A) those short lines connected
B) the short lines which
C) connected by short lines
D) short connecting lines
E) short lines that connected
12. The dawn redwood appears _____________ some 100 million years ago in northern forests around the world.
A) was flourished
B) having to flourish
C) to have flourished
D) have flourished
E) to flourish
13. Although thunder and lightning are produced at the same time, light waves travel faster ___________,
so we see the lightning before we hear the thunder.
A) than sound waves do
B) than sound waves are
C) do sound waves
D) sound waves
E) than
14. The discovery of the halftone process in photography in 1881 made it ____________ photographs in books and newspapers.
A) the possible reproduction
B) possible to reproduce
C) the possibility of reproducing
D) possibly reproduced
E) possible taking
15. Speciation, ______________, results when an animal population becomes isolated by some factor, usually geographic.
A) form biological species
B) biological species are formed
C) which forming biological species
D) the formation of biological species
E) a sort of biological species
16. In its pure state, antimony has no important uses, but __________ with other substances; it is an extremely useful metal.
A) when combined physically or chemically
B) combined when physically or chemically
C) the physical and chemical combination
D) it is combined physically and chemically
E) combining physically and chemically