高二英語上冊全冊教案3
(4) the most convincing evidence of black holes comes from research into binary star systems. binary stars, as their name suggests ,are twin stars whose position in space affects each other. in some binary systems, astronomers have shown that there is an invisible companion star, a "partner" to the one which we can see in the sky. matter from the one we can see is being pulled towards the companion star. could this invisible star, which exerts such a great force , be a black hole? astronomers have evidence of a few other stars too, which might have black holes as companions.
(5) the story of black holes is just beginning . speculations about them are endless. there might be a massive black hole at the center on our galaxy swallowing up stars at a very rapid rate. mankind may one day meet this fate. on the other hand, scientists have suggested that very advanced technology could one day make use of the energy of black holes for mankind. these speculations sound like science fiction. but the theory of black holes in space is accepted by many serious scientists and astronomers .they show us a world which operates in a totally different way from our own and they question our most basic experience of space and time.
read the passage carefully and choose the best answer for the following questions
1) black holes are related to ____
a. geography b. astronomy c. physics d. economic
2) a black hole is ____
a. a dark star b. a large heavenly body
c. a region of space d. a great mass of matter
3) what causes some stars to explode, theoretically speaking ?
a. their density b. their gravity. c. their movement d. their light
4) scientists call the area around the black hole ____.
a. a white dwarf b. a supernova
c. the event horizon d. the star of bethlehem
5) according to einstein's relativity theory, there is no "absolute " time and space. is it true or false?
a. true b. false
6) which of the following statements is not true? the story of black holes in space____
a. is accepted by many serious scientists and astronomers
b. has to some extent been proved by research into binary star system
c. is questioning our basic idea of space and time
d. sounds like science fiction
7) according to the passage , our earth may be swallowing by the black hole one day, is it true or false ?
a. true b. false
8) according to the passage , the human being one day may make use of the energy of black hole by advanced technology. is it true or false?