题目

Exciting as its special effects are ______, there is too much violence in the film.     A. to watch       B. to be watched  C. watching          D. being watched   答案：A如图所示，有5000个质量均为m的小球，将它们用长度相等的轻绳依次连接，再将其左端用细绳固定在天花板上，右端施加一水平力使全部小球静止。若连接天花板的细绳与水平方向的夹角为45°。则第201 1个小球与2012个小球之间的轻绳与水平方向的夹角α的正切值等于 （   ） A．           B．              C．           D．