更多"The explosion of a star is an aweso"的相关试题:
[单项选择]The explosion of a star is an awesome event. The most violent of these cataclysms, which produce supernovae, probably destroys a star completely. Within our galaxy of roughly 100 billion stars the last supernova was observed in 1604. Much smaller explosions, however, occur quite frequently, giving rise to what astronomers call novae and dwarf novae. On the order of 25 novae occur in our galaxy every year, but only two or three are near enough to be observed. About 100 dwarf novae are known altogether. If the exploding star is in a nearby part of the galaxy, it may create a "new star" that was not previously visible to the naked eye. The last new star of this sort that could be observed clearly from the Northern Hemisphere appeared in 1946. In these smaller explosions the star loses only a minute fraction of its mass and survives to explode again.
Astrophysicists are fairly well satisfied that they can account for the explosions of supernovae. The novae and dwarf novae have present
A. occurs about 25 times a year
B. last occurred in 1946
C. results in a new star
D. last was seen in 1604
[单项选择]
On Jan. 13, 1999, American basketball super-star Michael Jordan announced his retirement from the National Basketball Association (NBA). Speaking before a large crowd of journalists at the United Center in Chicago, Jordan stated that his decision to retire had been prompted by a feeling that he had no more challenges to overcome in the world of professional basketball. The 35-year-old Michael Jordan, who led the Bulls to their sixth championship in eight years during the 1997-98 season, also emphasised that he wished to retire while "knowing that he could still play the game". In announcing his retirement, Jordan officially brought an end to his unparalleled 13-year career in the NBA.
When did Michael Jordan announce his retirement from basketball().
A. Dec. 13, 1998.
B. Dec. 20, 1998.
C. Jan. 13, 1999.
D. Jan. 20, 1999.
[单项选择]Where did the explosion take place
A. In a super market
B. In an animal market
C. In a stock market.
[单项选择]What was the cause of the explosion
A. Children playing with fire.
B. The setting off of fireworks in a house with explosives,
C. Sparks from a fireworks display falling on the warehouse,
D. The firing of a gun.
[简答题]Like the population explosion, the scientific and technological revolution began to pick up speed slowly during the eighteenth century. And this ongoing revolution has also suddenly accelerated exponentially. For example, it is now an axiom in many fields of science that more new and important discoveries have taken place in the last ten years than in the entire previous history of science. While no single discovery has had the kind of effect on our relationship to the earth that nuclear weapons have had on our relationship to warfare, it is nevertheless true that taken together, they have completely transformed our cumulative ability to exploit the earth for sustenance—making the consequences of unrestrained exploitation every bit as unthinkable as the consequences of unrestrained nuclear war.
[单项选择]How many adults were killed in the explosion
A. 22.
B. 9.
C. 75.
D. 13.
[填空题]With the explosion of excitement about the Internet, there seems to be another type of addiction that has invaded the human psyche.
I. Internet addiction or computer addiction: what to name the phenomenon
1) Internet Addiction Disorder
-- Some people seem to be too excited about the Internet.
2) Computer Addiction
-- Many people are attached only to their computers and don’t care about the Internet.
3) Cyberspace Addiction
-- an addiction to (1) ______ of experience created through computer engineering
-- many subtypes with (2) ______
·some are game and competition oriented
·some fulfill more (3) ______
·some are an extension of workaholicism
Ⅱ. Normal enthusiasm and abnormal preoccupation: where to draw the line
1) Addictions can be healthy, unhealthy or (4) ______.
-- healthy: an outlet for learning, creativity and self-expression
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