I had wanted to help you last night but I couldn’t spare any time．for I_____an essay that is due this morning．

A．wrote

B．had written

C．was writing

D．have written

痛经的理论根据是( )

A．气血阻滞

B．气血虚弱

C．不通则痛或不荣则痛

D．气血外溢

E．以上均不是