题目

如图所示，人拉着旅行箱前进，拉力F与水平方向成α角，若将拉力F沿水平和竖直方向分解，则它的竖直分力为（ ） A . Fsinα B . Fcosα C . Ftanα D . Fcotα 答案：A Who can help me find information about Elvis Presley ________ I need to give a talk about western music? [　　] A．who B．whom C．what D．which