Facing this ________ problem, I found myself ________ about how to work it out.

A．puzzled; puzzled

B．puzzled; puzzling

C．puzzling; puzzling

D．puzzling; puzzled

建设工程监理工作文件中的监理大纲是( )时编制的。

A．监理单位在投标

B．建设单位在招标

C．监理单位在签订合同

D．监理单位在实施监理