单选题Sometimes it is advisable to book hotels in advance. A. possible B. profitable C. easy D. wise
单选题From the information given in the passage, most minerals would melt fastest _______.
单选题
下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断；如果该句提的是正确信息，请选择A；如果该句提的是错误信息，请选择B；如果该句的信息文中没有提及，请选择C。
Black Holes Most
scientists agree that black holes exist but are nearly impossible to locate. A
black hole in the universe is not a solid object, like a planet, but it is
shaped like a sphere (球体). Astronomers (天文学家) think that at the center of a
black hole there is a single point in space with infinite(无限的)density(稠密), This
single point is called a singularity (奇点). If the singularity theory is correct,
it means that when a massive star collapses, all the material in it disappears
into the singularity. The center of a black hole would not really be a hole at
all, but an infinitely dense point. Anything that crosses the black hole is
pulled in by its great gravity. Although black holes do exist,
they are difficult to observe. These are the reasons. · No light
or anything else comes out of black holes. As a result, they are invisible to a
telescope. · In astronomical terms, black holes are truly. For
example, a black hole formed by the collapse of a giant star would have an event
horizon(视界) only 18 miles across. · The nearest black holes
would be dozens of light years away from Earth. One light year is about 6
trillion (万亿) miles. Even the most powerful telescopes could not pick out an
object so small at such a great distance. In 1994 the Hubble
Space Telescope provided evidence that black holes exist. There are still
answers to be found, however, so black holes remain one of the mysteries of the
universe.
单选题She always
finds fault with
everything.
单选题It has been said that the Acts provided a new course of action and did not merely regulate or enlarge an old one. A．manage B．control C．revise D．outset
单选题The story was published with the Usole /U purpose of selling newspapers
单选题This text is too difficult to
comprehend
.
单选题American scientists predicted that Mount Saint Helens was to erupt soon.
单选题She cried aloud {{U}}all at once{{/U}}.
A. for a long time
B. suddenly
C. for no reason
D. quickly
单选题 阅读下面这篇短文，短文后列出7个句子，请根据短文的内容对每个句子做出判断。
{{B}}The Ice Age{{/B}} Twenty thousand
years ago, the earth was held in control by relentlessly (不宽容地) probing fingers
of ice that drew power from frigid strongholds in the north and crept
southwestward to bury forests, fields, and mountains. Landscapes that were
violated by the slowly moving glaciers(冰川 )would carry the scars of this advance
far into the future. Temperatures dropped deeply, and land surfaces in many
parts of the world were depressed by the unrelenting weight of the thrusting
ice. At the same time, so much was drawn from the oceans to form these huge
glaciers that sea levels around the world fell by three hundred and fifty feet,
and large areas of the continental shelf became dry land. This
period of the Earth's history had come to be called the Ice Age. In all, about
eleven million square miles of land were covered with ice. The Ice Age
terminated about fourteen thousand years ago when the ice sheets began to
retreat. It took about seven thousand years for the ice to retreat to its
present level.
单选题Dark Forces Dominate Universe
The earth, moon, sun and all visible stars in the sky make up less than one percent of the universe. Almost all the rest is dark matter and dark energy, unknown forces that
1
astronomers.
Observations in recent years have changed the basic
2
of how the universe evolved and have indicated how little is known about the major forces and substances that
3
our world. Astronomers now know that luminous (发光的) matter—stars, planets and hot gas—accounts
4
only about 0.4 percent of the universe. Non-luminous components, such as black holes and intergalactic (星间的) gas,
5
up 3.6 percent. The rest is either dark matter, about 23 percent, or dark energy, about 73 percent.
Dark matter, sometimes
6
"cold dark matter", has been known for some time. Only recently have researchers come to understand the key role it
7
in the formation of stars, planets and even people.
"We
8
our very existence to dark matter," said physicist Paul Steinhardt and a co-author of a review on dark matter which
9
not long ago in the journal Science. "Dark matter dominated the structure
10
in the early universe," Steinhardt said. "For the first few billion years dark matter contained most of the mass of the universe. You can think of ordinary matter
11
a froth (泡沫) of an ocean of dark matter. The dark matter dumps (结成块) and the ordinary matter falls into it. That
12
to the formation of the stars and galaxies (星系)." Without dark matter, there would be virtually no structures in the universe.
The nature of dark matter is
13
. It cannot be seen or detected directly. Astronomers know it is there because of its
14
on celestial (天体的) objects that can be seen and measured. But the most dominating force of all in the universe is called dark energy, a recently
15
power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed.
单选题Manufacturers spend millions of dollars on advertising to {{U}}entice{{/U}} people to buy their products.
单选题He Was rather {{U}}vague{{/U}} about the reasons why he never finished school．
单选题Please give my best
wishes
to your family.
单选题The Railway Labor Mediation Act of 1926 supported the use of collective bargaining to {{U}}avert{{/U}} interruption of rail service.
单选题There is a small
risk
of brain damage from such an operation.
单选题You will be eligible to vote next year. A. competent B. possible C. enough D. allowed
单选题His claims seem
credible
to many people.
单选题It is very difficult for a child to {{U}}adhere to{{/U}} rules.
A. follow
B. remember
C. understand
D. learn
单选题It doesn't {{U}}stand to reason{{/U}} that he would lie,