题干
China Today attracts a worldwider readership shows that more and more people all over the world want to learn about China.
A：who
B：whom
C：that
D：which
答案(点此获取答案解析）
D
＝
(其中c为光速，G为引力常量)，则该黑洞表面重力加速度的数量级为 ( )