如图所示，AC是半径为3m的光滑圆弧槽，圆弧与水平面相切于A点，底边长为AB=8cm，高为BC=5cm．现将小球先后从顶点C和圆弧AC的中点D静止起释放，则两次运动到A点的时间t_C和t_D的关系是（　　）

A．t_C＞t_D

B．t_C＜t_D

C．t_C=t_D

D．无法确定

In his speech, he said that it was his primary school teachers that he was fond of ________influenced his whole life.

A．what

B．which

C．as

D．who