We define time travel to mean departure from a certain place and time followed (from the traveler’s point of view) by arrival at the same place at an earlier time (from the sedentary observer’s point of view). Time travel paradoxes arise from the fact that departure occurs after arrival according to one observer and before arrival according to another. In the terminology of special relativity time travel implies that the time-like ordering of events is not invariant. This violates our intuitive notions of cause-effect relation. However, intuition is not an infallible guide, so we must be careful. Is time travel really impossible, or is it merely another phenomenon where "impossible" means "nature is more mysterious than we think" The answer is more interesting than you might think.
The B-movie image of the brave chrononaut climbing into his time machine and watching the clock outside spin backwards while those outside the time machine watch
Unlike most sports, which evolved over time from street games, basketball was (31) by one man to suit a particular purpose. The man was Dr. James Naismith, and his purpose was to invent a (32) game that could be played indoors in the winter.
In 1891, Naismith was an instructor at a training school, which trained physical education instructors for the YMCAs. That year the school was trying (33) up with a physical activity that the men could enjoy (34) the football and baseball seasons. None of the standard indoor activities (35) their interest for long. Naismith was asked to solve the problem by the school.
He first tried to (36) some of the popular outdoor sports, but they were all too rough. The men were getting bruised from (37) each other and (38) hit with equipment. So, he decided to invent a game that would incorporate the most common elements of outdoor team sports without having the real physical (3
A. abrupt
B. immediate
C. expected
D. right
我来回答:
