问题详情

Paragraph 4 __________ 查看材料
A.Is there proof that black holes really exist？
B.What are different types of black holes？
C.How are black holes formed？
D.How were black holes named？
E.What happens to the objects around a black hole？
F.What are black holes made of ？请帮忙给出正确答案和分析，谢谢！