If you don't know , please come to me.
A：who talk to
B：who will talk to
C：who to talk to
D：who to talk
被称为“日光城”的城市是
已知函数f（x）=xsinx，则f'π2=____
球迷小王和小李在观看一场重要比赛时，都表现出了情绪激动、心跳加快、血压升高、面红耳赤等现象．这是由于其体内哪类激素作用的结果？（ ）
