问题详情

Suppose that, in each trial, either electrons or protons had been added to each sphere to produce its charge. In Trial 3, which of the 2 types of particles would have been added to Sphere X, and which of the 2 types of particles would have been added to Sphere Y ？

A.electrons；protons

B.protons；electrons

C.electrons；electrons

D.protons；protons

请帮忙给出正确答案和分析，谢谢！