In order to obtain the needed information, you should write simply, clearly, and con cisely ______ the reader wants to know.

A．what

B．that

C．so that

D．which

手术后急性疼痛可引起机体释放的内源性物质不包括()

A．儿茶酚胺

B．醛固酮

C．血管升压素

D．皮质醇

E．甲状腺素