TOEFL Practice Test #8

Question 1

______ aluminum is exposed to oxygen, a tough, invisible oxide forms, making it extremely corrosion-resistant.

Accepted Answer

Once

Answer

No sooner than

Answer

So soon that

Answer

The sooner

Question 2

______ the Silurian Period, there was significant radiation of rapacious fish equipped with bulky jaws.

Accepted Answer

During

Answer

When

Answer

Since

Answer

Until

Question 3

Sickle-cell anemia, which is a genetic defect, is caused by ____ that encourages a faulty form of hemoglobin.

Accepted Answer

a certain mutant allele

Answer

mutant a certain allele

Answer

a mutant allele certain

Answer

an allele certain mutant

Question 4

Mary McLeod Bethune, a leading African-American _____, as a child attended the local free school.

Accepted Answer

educator

Answer

educator who

Answer

educator she

Answer

whose education

Question 5

Beryllium is used as a bonding agent for nuclear fuel elements ____ toughness and excellent resistance to heat.

Accepted Answer

because of its

Answer

although its

Answer

it is when

Answer

that its

Question 6

After the wine is clarified, it _____ in wooden kegs or stainless  steel tanks to age.

Accepted Answer

is kept

Answer

keeps

Answer

had been kept

Answer

keeping

Question 7

Amphibians thrive in humid areas, nevertheless, their habitats are constantly decreased __________ new construction.

Accepted Answer

due to

Answer

because

Answer

for

Answer

since

Question 8

Natural rubber is an exceptionally useful raw material because it retains air, keeps out moisture, and does not ______ electricity.

Accepted Answer

conduct

Answer

conductor

Answer

conducting

Question 9

After a rainfall in the desert, the water _____ in the playas either vaporizes or trickles down into the earth.

Accepted Answer

collected

Answer

was collected

Answer

has collected

Answer

to collect

Question 10

Select the right response. Sunspots are by far the most obvious flaws on the Sun's surface.

Accepted Answer

are

Answer

That are

Answer

the

Answer

in the