—What were you doing when I called you at 8 p.m. yesterday?  

—I      the piano at that time.

A．play

B．is playing

C．played

D．was playing

A型药物不良反应（）。

A.与剂量有关，可以预测，发生率高，死亡率低

B.与剂量无关，可以预测，发生率高，死亡率低

C.与剂量有关，很难预测，发生率高，死亡率亦高

D.与剂量无关，很难预测，发生率高，死亡率低

E.与剂量有关，可以预测，发生率低，死亡率高