. One of the strangest phenomena in the universe is the black hole. Like vacuum cleaners, black holes will suck up anything (1) _______ crosses their path. Since they are able to pull in light, black holes are nearly impossible to see even with high-powered telescopes. (2) _______ , scientists are able to detect the presence of black holes in space because of their effect on an observed area. Black holes may also occur when several large and dense stars collide with one (3) ______ in space.

Question 1: A. who                      B. whose            C. what                         D. that

Question 2: A. Moreover              B. In fact           C. However                   D. Therefore

Question 3: A. other                     B. another          C. others                        D. each

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