A．clearly a super-massive black holeB．a compact cluster……

单项选择题Were it not for the new telescope high in the Andes Mountains, researchers would not have argued that ______.

单项选择题It may be inferred from the passage that jets of gas ______.

单项选择题According to the passage, which of the following is TRUE

单项选择题According to the German researchers, the energy source at the center of the Milky Way Galaxy ______.