---I heard that you made a bicycle trip to the 2010 World Expo of Shanghai alone.

---No. Actually, my friend Bob ________ me.

A．accompanied

B．conducted

C．instructed

D．received

下列关于电解水的叙述错误的是（　　）

A．电解水实验证明水是由氢、氧两种元素组成的

B．电解水时正、负极产生的气体体积比约为1：2

C．为增强水的导电性，常在水中加入少量的稀硫酸

D．与电源正极相连的试管内得到的气体能在空气中燃烧