链接控制面板中名前方的“？”表示；（）
A.此链接文件已丢失
B.此链接文件被更改
C.此链接文件的文件格式错
D.此链接文件颜色模式错
参考答案：A
两颗行星的质量分别为m1、m2，它们绕太阳运转轨道的半长轴分别为R1、R2，如果m1=2m2，R1=4R2，那么，它们的运行周期之比T1：T2=______．
Fearful that rapidly modernizing Korean rivals will intrude on its foreign and domestic markets, Japan has fought to keep the Koreans from appropriating its technologies. ( )
A．competitors
B．representatives
C．negotiators
D．dealers
