—Why didn’t you put your cellphone in your overcoat pocket?

—I      , but I was afraid it would be stolen.

A．had put

B．put

C．would have

D．could have

根据调查研究内容的不同表现方法，调研型科技论文主干部分的结构包括（）

A.纵式结构

B.交错对比式

C.纵横结合式

D.横式结构

E.对比结构