The lady gave all the money to charity _________she wasn’t rich.

A. if                        B. because                C. though

用与丝绸摩擦过的玻璃棒去靠近细线悬挂的轻质小球时，产生了互相吸引的现象。则该小球[ ]

A.一定带正电

B.一定带负电

C.可能带正电

D.可能不带电