A:read
B:fetch
C:direct
D:approve
读图“地震波速度与地球内部构造图”,完成下题.
John is ______ a birthday party in his house with his good friends. ( )
世界陆地表面最低处是( )
小刚同学做“弹簧的伸长与所受拉力的关系”的探究实验,记录数据如下: