On his way home, he found a wallet ____ on the ground, which he picked up and ____ in his schoolbag.

A．laid; lay

B．laying; laid

C．lying; laid

D．lain; lay

下列对于影响绝缘电阻测量结果的因素的表述，正确的是（）。

A.温度升高，绝缘电阻降低

B.大气湿度增加，绝缘电阻降低

C.测量之后的放电时间对下次测量的准确性有影响

D.温度升高，绝缘电阻降低