题干
It is not J. K. Rowling but her works that _____ us excited.
A：make
B：is made
C：make
D：are made
答案(点此获取答案解析）
C
A：make
B：is made
C：make
D：are made
的正方形的四个顶点上．已知引力常量为G．关于四星系统，下列说法错误的是（忽略星体自转）（ ）