Some of the low-end Made-in-China mechanical-electronic products are not selling well in export market as compared with what are termed as high-end ones.

A．on export market

B．in exporting market

C．in exported market

D．in the export market

通常来讲，物理学和心理学研究之间的区别在于（）。

A.物性内蕴，人性内显

B.物性外蕴，人性外显

C.物性外显，人性内蕴

D.人性外显，物性内蕴