单选题 Electrical resistance is a common property of all materials, ______.
A. only differs in degree B. only in degree it differs
C. differing only in degree D. and differing in degree only

【正确答案】 C
【答案解析】[解析] 现在分词短语作让步状语，全句意思为：电阻是所有物质的共性，只是存在大小差异罢了。